Minimally invasive surgery instrument assembly with reduced cross section

ABSTRACT

A surgical instrument extends through a guide tube and exits at an intermediate position of the guide tube. The instrument includes a parallel motion mechanism that changes the position of a distal end of the surgical instrument without changing the orientation of the distal end. An image capture component is at the distal end of the guide tube, and a joint allows the image capture component to move while the intermediate position remains stationary. The configuration allows a cross section of the guide tube to be oblong. In some aspects, a joint for the image capture component is placed between exit ports for surgical instruments, which allows the guide tube cross section to be further reduced.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of the following U.S.Provisional Patent Applications, all of which are incorporated byreference:

-   -   U.S. Patent Application No. 60/813,028 entitled “Single port        system 2” filed 13 Jun. 2006 by Cooper et al.;    -   U.S. Patent Application No. 60/813,029 entitled “Single port        surgical system 1” filed 13 Jun. 2006 by Larkin;    -   U.S. Patent Application No. 60/813,030 entitled “Independently        actuated optical train” filed 13 Jun. 2006 by Larkin et al.;    -   U.S. Patent Application No. 60/813,075 entitled “Modular cannula        architecture” filed 13 Jun. 2006 by Larkin et al.;    -   U.S. Patent Application No. 60/813,125 entitled “Methods for        delivering instruments to a surgical site with minimal        disturbance to intermediate structures” filed 13 Jun. 2006 by        Larkin et al.;    -   U.S. Patent Application No. 60/813,126 entitled “Rigid single        port surgical system” filed 13 Jun. 2006 by Cooper;    -   U.S. Patent Application No. 60/813,129 entitled “Minimum net        force actuation” filed 13 Jun. 2006 by Cooper et al.;    -   U.S. Patent Application No. 60/813,131 entitled “Side working        tools and camera” filed 13 Jun. 2006 by Duval et al.;    -   U.S. Patent Application No. 60/813,172 entitled “Passing cables        through joints” filed 13 Jun. 2006 by Cooper;    -   U.S. Patent Application No. 60/813,173 entitled “Hollow smoothly        bending instrument joints” filed 13 Jun. 2006 by Larkin et al.;    -   U.S. Patent Application No. 60/813,198 entitled “Retraction        devices and methods” filed 13 Jun. 2006 by Larkin et al.;    -   U.S. Patent Application No. 60/813,207 entitled “Sensory        architecture for endoluminal robots” filed 13 Jun. 2006 by        Diolaiti et al.; and    -   U.S. Patent Application No. 60/813,328 entitled “Concept for        single port laparoscopic surgery” filed 13 Jun. 2006 by Mohr et        al.

In addition, this application is related to the following concurrentlyfiled U.S. Patent Applications, all of which are incorporated byreference:

-   -   U.S. patent application Ser. No. 11/762,217 entitled “Retraction        of tissue for single port entry, robotically assisted medical        procedures” by Mohr;    -   U.S. patent application Ser. No. 11/762,222 entitled “Bracing of        bundled medical devices for single port entry, robotically        assisted medical procedures” by Mohr et al.;    -   U.S. patent application Ser. No. 11/762,231 entitled “Extendable        suction surface for bracing medical devices during robotically        assisted medical procedures” by Schena;    -   U.S. patent application Ser. No. 11/762,236 entitled “Control        system configured to compensate for non-ideal actuator-to-joint        linkage characteristics in a medical robotic system” by Diolaiti        et al.;    -   U.S. patent application Ser. No. 11/762,185 entitled “Surgical        instrument actuation system” by Cooper et al.;    -   U.S. patent application Ser. No. 11/762,172 entitled “Surgical        instrument actuator” by Cooper et al.;    -   U.S. patent application Ser. No. 11/762,165 entitled “Minimally        invasive surgical system” by Larkin et al.;    -   U.S. patent application Ser. No. 11/762,161 entitled “Minimally        invasive surgical instrument advancement” by Larkin et al.;    -   U.S. patent application Ser. No. 11/762,158 entitled “Surgical        instrument control and actuation” by Cooper et al.;    -   U.S. patent application Ser. No. 11/762,154 entitled “Surgical        instrument with parallel motion mechanism” by Cooper;    -   U.S. patent application Ser. No. 11/762,149 entitled “Minimally        invasive surgical apparatus with side exit instruments” by        Larkin;    -   U.S. patent application Ser. No. 11/762,170 entitled “Minimally        invasive surgical apparatus with side exit instruments” by        Larkin;    -   U.S. patent application Ser. No. 11/762,143 entitled “Minimally        invasive surgical instrument system” by Larkin;    -   U.S. patent application Ser. No. 11/762,135 entitled “Side        looking minimally invasive surgery instrument assembly” by        Cooper et al.;    -   U.S. patent application Ser. No. 11/762,132 entitled “Side        looking minimally invasive surgery instrument assembly” by        Cooper et al.;    -   U.S. patent application Ser. No. 11/762,127 entitled “Guide tube        control of minimally invasive surgical instruments” by Larkin et        al.;    -   U.S. patent application Ser. No. 11/762,123 entitled “Minimally        invasive surgery guide tube” by Larkin et al.;    -   U.S. patent application Ser. No. 11/762,120 entitled “Minimally        invasive surgery guide tube” by Larkin et al.;    -   U.S. patent application Ser. No. 11/762,118 entitled “Minimally        invasive surgical retractor system” by Larkin;    -   U.S. patent application Ser. No. 11/762,114 entitled “Minimally        invasive surgical illumination” by Schena et al.;    -   U.S. patent application Ser. No. 11/762,110 entitled “Retrograde        instrument” by Duval et al.;    -   U.S. patent application Ser. No. 11/762,204 entitled “Retrograde        instrument” by Duval et al.;    -   U.S. patent application Ser. No. 11/762,202 entitled “Preventing        instrument/tissue collisions” by Larkin;    -   U.S. patent application Ser. No. 11/762,191 entitled “Minimally        invasive surgical system” by Larkin et al.;    -   U.S. patent application Ser. No. 11/762,196 entitled “Minimally        invasive surgical system” by Duval et al.; and    -   U.S. patent application Ser. No. 11/762,200 entitled “Minimally        invasive surgical system” by Diolaiti, issued as U.S. Pat. No.        7,725,215 on May 25, 2010.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

None.

BACKGROUND

1. Field of Invention

Aspects of the invention are associated with systems and procedures usedfor minimally invasive surgery, and more particularly totelemanipulative systems used for such surgery.

2. Background Art

Minimally invasive surgery is known under various names (e.g.,endoscopy, laparoscopy, arthroscopy, endovascular, keyhole, etc.), oftenspecific to the anatomical area in which work is done. Such surgeryincludes the use of both hand-held andteleoperated/telemanipulated/telepresence (robot assisted/telerobotics)equipment, such as the da Vinci® Surgical System made by IntuitiveSurgical, Inc. of Sunnyvale, Calif. Both diagnostic (e.g., biopsy) andtherapeutic procedures are done. Instruments may be inserted into apatient percutaneously via surgical incision or via natural orifice. Anew, experimental minimally invasive surgery variation is NaturalOrifice Transluminal Endoscopic Surgery (NOTES), in which instrumentsenter via a natural orifice (e.g., mouth, nostril, ear canal, anus,vagina, urethra) and continue to a surgical site via a transluminalincision (e.g., in a gastric or colonic wall) within the body. Althoughteleoperative surgery using the da Vinci® Surgical System provides greatbenefits over, for instance, many hand-held procedures, for somepatients and for some anatomical areas the da Vinci® Surgical System isunable to effectively access a surgical site. In addition, furtherreducing the size and number of incisions aids patient recovery andhelps reduce patient trauma and discomfort.

The number of degrees of freedom (DOPs) is the number of independentvariables that uniquely identify the pose/configuration of a system.Since robotic manipulators are kinematic chains that map the (input)joint space into the (output) Cartesian space, the notion of DOF can beexpressed in any of these two spaces. In particular, the set of jointDOFs is the set of joint variables for all the independently controlledjoints. Without loss of generality, joints are mechanisms that provide asingle translational (prismatic joints) or rotational (revolute joints)DOF. Any mechanism that provides more than one DOF motion is considered,from a kinematic modeling perspective, as two or more separate joints.The set of Cartesian DOFs is usually represented by the threetranslational (position) variables (e.g., surge, heave, sway) and by thethree rotational (orientation) variables (e.g. Euler angles orroll/pitch/yaw angles) that describe the position and orientation of anend effector (or tip) frame with respect to a given reference Cartesianframe.

For example, a planar mechanism with an end effector mounted on twoindependent and perpendicular rails has the capability of controllingthe x/y position within the area spanned by the two rails (prismaticDOFs). If the end effector can be rotated around an axis perpendicularto the plane of the rails, then there are then three input DOFs (the tworail positions and the yaw angle) that correspond to three output DOFs(the x/y position and the orientation angle of the end effector).

Although the number of Cartesian DOFs is at most six, a condition inwhich all the translational and orientational variables areindependently controlled, the number of joint DOFs is generally theresult of design choices that involve considerations of the complexityof the mechanism and the task specifications. Accordingly, the number ofjoint DOFs can be more than, equal to, or less than six. Fornon-redundant kinematic chains, the number of independently controlledjoints is equal to the degree of mobility for the end effector frame.For a certain number of prismatic and revolute joint DOFs, the endeffector frame will have an equal number of DOFs (except when insingular configurations) in Cartesian space that will correspond to acombination of translational (x/y/z position) and rotational(roll/pitch/yaw orientation angle) motions.

The distinction between the input and the output DOFs is extremelyimportant in situations with redundant or “defective” kinematic chains(e.g., mechanical manipulators). In particular, “defective” manipulatorshave fewer than six independently controlled joints and therefore do nothave the capability of fully controlling end effector position andorientation. Instead, defective manipulators are limited to controllingonly a subset of the position and orientation variables. On the otherhand, redundant manipulators have more than six joint DOFs. Thus, aredundant manipulator can use more than one joint configuration toestablish a desired 6-DOF end effector pose. In other words, additionaldegrees of freedom can be used to control not just the end effectorposition and orientation but also the “shape” of the manipulator itself.In addition to the kinematic degrees of freedom, mechanisms may haveother DOFs, such as the pivoting lever movement of gripping jaws orscissors blades.

It is also important to consider reference frames for the space in whichDOFs are specified. For example, a single DOF change in joint space(e.g., the joint between two links rotates) may result in a motion thatcombines changes in the Cartesian translational and orientationalvariables of the frame attached to the distal tip of one of the links(the frame at the distal tip both rotates and translates through space).Kinematics describes the process of converting from one measurementspace to another. For example, using joint space measurements todetermine the Cartesian space position and orientation of a referenceframe at the tip of a kinematic chain is “forward” kinematics. UsingCartesian space position and orientation for the reference frame at thetip of a kinematic chain to determine the required joint positions is“inverse” kinematics. If there are any revolute joints, kinematicsinvolves non-linear (trigonometric) functions.

SUMMARY

In accordance with aspects of the invention, a surgical instrumentextends through a guide tube and exits at an intermediate position ofthe guide tube. The instrument includes a parallel motion mechanism thatchanges the position of a distal end of the surgical instrument withoutchanging the orientation of the distal end. An image capture componentis at the distal end of the guide tube, and a joint allows the imagecapture component to move while the intermediate position remainsstationary. The configuration allows a cross section of the guide tubeto be oblong. In addition, if the joint for the image capture componentis placed between exit ports for surgical instruments, then the guidetube cross section can be further reduced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of a minimally invasive surgicalinstrument and its motion about a pivot point represented by an incisionor natural orifice.

FIG. 2A is a diagrammatic view of another minimally invasive surgicalinstrument and its motion.

FIG. 2B is a diagrammatic view of yet another minimally invasivesurgical instrument and its motion.

FIG. 3 is a schematic view of a minimally invasive surgical instrument.

FIG. 4 is a schematic view that illustrates aspects of a minimallyinvasive surgical instrument assembly.

FIGS. 4A and 4B are diagrammatic perspective views that illustrateaspects of a removable instrument that is held in place within guidetube.

FIG. 5 is a schematic view that illustrates aspects of a secondminimally invasive surgical instrument assembly.

FIG. 6 is a schematic view that illustrates aspects of a third minimallyinvasive surgical instrument assembly.

FIG. 7 is a schematic view that illustrates aspects of a fourthminimally invasive surgical instrument assembly.

FIG. 8 is a schematic view that illustrates aspects of a fifth minimallyinvasive surgical instrument assembly.

FIG. 9 is a schematic view that illustrates aspects of a sixth minimallyinvasive surgical instrument assembly.

FIG. 9A is a schematic view that illustrates a detail of an alternateaspect of FIG. 9.

FIG. 10 is a schematic view that illustrates aspects of a seventhminimally invasive surgical assembly.

FIG. 11 is a schematic view that illustrates aspects of an eighthminimally invasive surgical assembly.

FIGS. 11A and 11B are diagrammatic end views of surgical instrumentassemblies.

FIG. 12 is a schematic view that illustrates aspects of a ninthminimally invasive surgical instrument assembly.

FIGS. 12A and 12B are diagrammatic views of retroflexive positions.

FIG. 13 is a schematic view that illustrates aspects of a tenthminimally invasive surgical instrument assembly.

FIG. 14 is a schematic view that illustrates aspects of an eleventhminimally invasive surgical instrument assembly.

FIGS. 15A-15D are schematic views that illustrate aspects of inserting aflexible, steerable surgical instrument and surgical instrumentassembly.

FIG. 16 is a schematic view that illustrates a twelfth aspect of aminimally invasive surgical instrument assembly.

FIG. 16A is a side elevation view of an embodiment of the distal portionof a minimally invasive surgical instrument that includes a parallelmotion mechanism.

FIG. 16B is a perspective view, and FIG. 16C is a cross-sectional view,of an embodiment of joints in a parallel motion mechanism.

FIGS. 16D and 16E are schematic views that illustrate design andoperation aspects of a parallel motion mechanism.

FIGS. 16F and 16G are diagrammatic end views of link disks in a parallelmotion mechanism.

FIGS. 16H and 16I are diagrammatic perspective views of stiffeningbrackets in a parallel motion mechanism.

FIG. 16J is a diagrammatic end view of a stiffening bracket.

FIG. 17 is a schematic view that illustrates aspects of a thirteenthminimally invasive surgical instrument assembly.

FIG. 17A is a schematic side view of a detail of FIG. 17.

FIG. 17B is a diagrammatic perspective view of a surgical instrumentassembly.

FIG. 18 is a schematic view that illustrates aspects of a fourteenthminimally invasive surgical instrument assembly.

FIG. 18A is a schematic view that illustrates aspects of an imagingsystem at the distal end of an instrument assembly.

FIG. 18B is a schematic view that shows that illustrates aspects ofimaging system movement.

FIG. 18C is a diagrammatic perspective view of a minimally invasivesurgical instrument assembly.

FIG. 18D is a diagrammatic perspective view that illustrates how adistal end of a surgical instrument assembly pitches up and down.

FIG. 18E is another diagrammatic perspective view of a minimallyinvasive surgical instrument assembly.

FIG. 18F is a diagrammatic plan view of a surgical instrument assemblywith a movable imaging system at the distal tip of a guide tube, andFIG. 18G is a diagrammatic detail that shows an alternate aspect of thesurgical instrument assembly shown in FIG. 18F.

FIG. 19 is a diagrammatic perspective view that illustrates aspects of afifteenth minimally invasive surgical instrument assembly.

FIG. 19A is another diagrammatic perspective view of the embodimentdepicted in FIG. 19.

FIG. 19B is a plan view of a surgical instrument assembly.

FIG. 19C is another plan view of the surgical instrument assembly shownin FIG. 19B.

FIG. 19D is an exploded perspective view that illustrates aspects of asurgical instrument mechanism.

FIG. 19E is a perspective view of cable guide tubes.

FIG. 19F is an end elevation view of cable guide tubes.

FIG. 19G is a perspective view of a cable guide piece.

FIG. 19H is a perspective view that illustrates aspects of a surgicalinstrument passing through and exiting from a guide tube.

FIG. 19I is a perspective view that illustrates aspects of a surgicalinstrument's motion after exiting from a guide tube.

FIG. 19J is a perspective view that illustrates aspects of a surgicalinstrument assembly with two retrograde surgical instruments.

FIG. 19K is a plan view of a surgical instrument assembly.

FIG. 20A is an end elevation view of the distal end face of a guidetube.

FIG. 20B is an end elevation view of the distal end face of guide tubeshown in FIG. 20A, with an imaging system and two surgical instruments.

FIG. 20C is an end elevation view that illustrates a guide tube with aninstrument channel that includes grooves arranged in a “V” shape.

FIGS. 20D, 20E, and 20F are each end elevation views that illustrateother guide tube channel configurations.

FIG. 21A is a schematic view of a robot-assisted minimally invasivetelesurgical system.

FIGS. 21B and 21C are schematic views of a patient side support systemin a telesurgical system.

FIG. 22A is a diagrammatic view of a centralized motion control systemfor a minimally invasive telesurgical system.

FIG. 22B is a diagrammatic view of a distributed motion control systemfor a minimally invasive telesurgical system.

FIG. 23 is a schematic view of an interface between a surgicalinstrument assembly and an actuator assembly.

FIG. 24A is a perspective view of the proximal segment of a minimallyinvasive surgical instrument.

FIG. 24B is a perspective view of a segment of an actuator assembly 2420that mates with and actuates the instrument shown in FIG. 24A.

FIG. 25A is a diagrammatic perspective view that illustrates mountingminimally invasive surgical instruments and actuator assemblies at theend of a setup arm.

FIG. 25B is another diagrammatic perspective view that illustratesmounting minimally invasive surgical instruments and actuator assembliesat the end of a setup arm.

FIG. 26A is a diagrammatic end view of instrument transmissionmechanisms and a guide tube.

FIGS. 26B, 26C, and 26D are diagrammatic end views of transmissionmechanisms spaced around a guide tube.

FIG. 26E is a diagrammatic exploded perspective view of an actuatorhousing and an instrument.

FIG. 27 is a diagrammatic view of transmission mechanisms associatedwith flexible coaxial guide tubes and instruments.

FIG. 28A is a diagrammatic view of multi-port surgery.

FIG. 28B is another diagrammatic view of multi-port surgery.

FIGS. 29A and 29B are diagrammatic views of minimally invasive surgicalinstrument assembly position sensing.

FIGS. 29C-29E are diagrammatic plan views that illustrate furtheraspects of preventing undesired instrument collision with tissue.

FIG. 29F is a diagrammatic view of an image mosaiced output display fora surgeon.

FIG. 30 is a schematic view of a mechanism for automatically exchangingminimally invasive surgical instruments.

FIG. 30A is a schematic view of storing an instrument or other componenton a drum.

FIG. 30B is a schematic view of storing automatically replaceableinstruments on spools.

FIG. 31 is a diagrammatic perspective view of an illustrative minimallyinvasive surgical instrument assembly that includes a multi-jointedinstrument dedicated to retraction.

DETAILED DESCRIPTION

This description and the accompanying drawings that illustrate aspectsand embodiments of the present invention should not be taken aslimiting—the claims define the protected invention. Various mechanical,compositional, structural, electrical, and operational changes may bemade without departing from the spirit and scope of this description andthe claims. In some instances, well-known circuits, structures, andtechniques have not been shown in detail in order not to obscure theinvention. Like numbers in two or more figures represent the same orsimilar elements.

Further, this description's terminology is not intended to limit theinvention. For example, spatially relative terms—such as “beneath”,“below”, “lower”, “above”, “upper”, “proximal”, “distal”, and thelike—may be used to describe one element's or feature's relationship toanother element or feature as illustrated in the figures. Thesespatially relative terms are intended to encompass different positionsand orientations of the device in use or operation in addition to theposition and orientation shown in the figures. For example, if thedevice in the figures is turned over, elements described as “below” or“beneath” other elements or features would then be “above” or “over” theother elements or features. Thus, the exemplary term “below” canencompass both positions and orientations of above and below. The devicemay be otherwise oriented (rotated 90 degrees or at other orientations),and the spatially relative descriptors used herein interpretedaccordingly. Likewise, descriptions of movement along and around variousaxes include various special device positions and orientations. Inaddition, the singular forms “a”, “an”, and “the” are intended toinclude the plural forms as well, unless the context indicatesotherwise. And, the terms “comprises”, “comprising”, “includes”, and thelike specify the presence of stated features, steps, operations,elements, and/or components but do not preclude the presence or additionof one or more other features, steps, operations, elements, components,and/or groups. Components described as coupled may be electrically ormechanically directly coupled, or they may be indirectly coupled via oneor more intermediate components.

Telemanipulation and like terms generally refer to an operatormanipulating a master device (e.g., an input kinematic chain) in arelatively natural way (e.g., a natural hand or finger movement),whereupon the master device movements are made into commands that areprocessed and transmitted in real time to a slave device (e.g., anoutput kinematic chain) that reacts nearly instantaneously to thecommands and to environmental forces. Telemanipulation is disclosed inU.S. Pat. No. 6,574,355 (Green), which is incorporated by reference.

To avoid repetition in the figures and the descriptions below of thevarious aspects and illustrative embodiments, it should be understoodthat many features are common to many aspects and embodiments. Omissionof an aspect from a description or figure does not imply that the aspectis missing from embodiments that incorporate that aspect. Instead, theaspect may have been omitted for clarity and to avoid prolixdescription.

Accordingly, several general aspects apply to various descriptionsbelow. For example, at least one surgical end effector is shown ordescribed in various figures. An end effector is the part of theminimally invasive surgical instrument or assembly that performs aspecific surgical function (e.g., forceps/graspers, needle drivers,scissors, electrocautery hooks, staplers, clip appliers/removers, etc.).Many end effectors have a single DOF (e.g., graspers that open andclose). The end effector may be coupled to the surgical instrument bodywith a mechanism that provides one or more additional DOFs, such as“wrist” type mechanisms. Examples of such mechanisms are shown in U.S.Pat. No. 6,371,952 (Madhani et al.) and in U.S. Pat. No. 6,817,974(Cooper et al.), both of which are incorporated by reference, and may beknown as various Intuitive Surgical, Inc. Endowrist® mechanisms as usedon both 8 mm and 5 mm instruments for the da Vinci® Surgical System.Although the surgical instruments described herein generally include endeffectors, it should be understood that in some aspects an end effectormay be omitted. For example, the distal tip of an instrument body shaftmay be used to retract tissue. As another example, suction or irrigationopenings may exist at the distal tip of a body shaft or the wristmechanism. In these aspects, it should be understood that descriptionsof positioning and orienting an end effector include positioning andorienting the tip of a surgical instrument that does not have an endeffector. For example, a description that addresses the reference framefor a tip of an end effector should also be read to include thereference frame of the a tip of a surgical instrument that does not havean end effector.

Throughout this description, it should be understood that a mono- orstereoscopic imaging system/image capture component/camera device may beplaced at the distal end of an instrument wherever an end effector isshown or described (the device may be considered a “camera instrument”),or it may be placed near or at the distal end of any guide tube or otherinstrument assembly element. Accordingly, the terms “imaging system” andthe like as used herein should be broadly construed to include bothimage capture components and combinations of image capture componentswith associated circuitry and hardware, within the context of theaspects and embodiments being described. Such endoscopic imaging systems(e.g., optical, infrared, ultrasound, etc.) include systems withdistally positioned image sensing chips and associated circuits thatrelay captured image data via a wired or wireless connection to outsidethe body. Such endoscopic imaging systems also include systems thatrelay images for capture outside the body (e.g., by using rod lenses orfiber optics). In some instruments or instrument assemblies a directview optical system (the endoscopic image is viewed directly at aneyepiece) may be used. An example of a distally positioned semiconductorstereoscopic imaging system is described in U.S. patent application Ser.No. 11/614,661 “Stereoscopic Endoscope” (Shafer et al.), which isincorporated by reference. Well-known endoscopic imaging systemcomponents, such as electrical and fiber optic illumination connections,are omitted or symbolically represented for clarity. Illumination forendoscopic imaging is typically represented in the drawings by a singleillumination port. It should be understood that these depictions areexemplary. The sizes, positions, and numbers of illumination ports mayvary. Illumination ports are typically arranged on multiple sides of theimaging apertures, or completely surrounding the imaging apertures, tominimize deep shadows.

In this description, cannulas are typically used to prevent a surgicalinstrument or guide tube from rubbing on patient tissue. Cannulas may beused for both incisions and natural orifices. For situations in which aninstrument or guide tube does not frequently translate or rotaterelative to its insertion (longitudinal) axis, a cannula may not beused. For situations that require insufflation, the cannula may includea seal to prevent excess insufflation gas leakage past the instrument orguide tube. For example, for thoracic surgery that does not requireinsufflation, the cannula seal may be omitted, and if instruments orguide tube insertion axis movement is minimal, then the cannula itselfmay be omitted. A rigid guide tube may function as a cannula in someconfigurations for instruments that are inserted relative to the guidetube. Cannulas and guide tubes may be, e.g., steel or extruded plastic.Plastic, which is less expensive than steel, may be suitable forone-time use.

Various instances and assemblies of flexible surgical instruments andguide tubes are shown and described. Such flexibility, in thisdescription, is achieved in various ways. For example, a segment or aninstrument or guide tube may be a continuously curving flexiblestructure, such as one based on a helical wound coil or on tubes withvarious segments removed (e.g., kerf-type cuts). Or, the flexible partmay be made of a series of short, pivotally connected segments(“vertebrae”) that provide a snake-like approximation of a continuouslycurving structure. Instrument and guide tube structures may includethose in U.S. Patent Application Pub. No. US 2004/0138700 (Cooper etal.), which is incorporated by reference. For clarity, the figures andassociated descriptions generally show only two segments of instrumentsand guide tubes, termed proximal (closer to the transmission mechanism;farther from the surgical site) and distal (farther from thetransmission mechanism; closer to the surgical site). It should beunderstood that the instruments and guide tubes may be divided intothree or more segments, each segment being rigid, passively flexible, oractively flexible. Flexing and bending as described for a distalsegment, a proximal segment, or an entire mechanism also apply tointermediate segments that have been omitted for clarity. For instance,an intermediate segment between proximal and distal segments may bend ina simple or compound curve. Flexible segments may be various lengths.Segments with a smaller outside diameter may have a smaller minimumradius of curvature while bending than segments with a larger outsidediameter. For cable-controlled systems, unacceptably high cable frictionor binding limits minimum radius of curvature and the total bend anglewhile bending. The guide tube's (or any joint's) minimum bend radius issuch that it does not kink or otherwise inhibit the smooth motion of theinner surgical instrument's mechanism. Flexible components may be, forexample, up to approximately four feet in length and approximately 0.6inches in diameter. Other lengths and diameters (e.g., shorter, smaller)and the degree of flexibility for a specific mechanism may be determinedby the target anatomy for which the mechanism has been designed.

In some instances only a distal segment of an instrument or guide tubeis flexible, and the proximal segment is rigid. In other instances, theentire segment of the instrument or guide tube that is inside thepatient is flexible. In still other instances, an extreme distal segmentmay be rigid, and one or more other proximal segments are flexible. Theflexible segments may be passive or they may be actively controllable(“steerable”). Such active control may be done using, for example, setsof opposing cables (e.g., one set controlling “pitch” and an orthogonalset controlling “yaw”; three cables can be used to perform similaraction). Other control elements such as small electric or magneticactuators, shape memory alloys, electroactive polymers (“artificialmuscle”), pneumatic or hydraulic bellows or pistons, and the like may beused. In instances in which a segment of an instrument or guide tube isfully or partially inside another guide tube, various combinations ofpassive and active flexibility may exist. For instance, an activelyflexible instrument inside a passively flexible guide tube may exertsufficient lateral force to flex the surrounding guide tube. Similarly,an actively flexible guide tube may flex a passively flexible instrumentinside it. Actively flexible segments of guide tubes and instruments maywork in concert. For both flexible and rigid instruments and guidetubes, control cables placed farther from the center longitudinal axismay provide a mechanical advantage over cables placed nearer to thecenter longitudinal axis, depending on compliance considerations in thevarious designs.

The flexible segment's compliance (stiffness) may vary from being almostcompletely flaccid (small internal frictions exist) to beingsubstantially rigid. In some aspects, the compliance is controllable.For example, a segment or all of a flexible segment of an instrument orguide tube can be made substantially (i.e., effectively but notinfinitely) rigid (the segment is “rigidizable” or “lockable”). Thelockable segment may be locked in a straight, simple curve or in acompound curve shape. Locking may be accomplished by applying tension toone or more cables that run longitudinally along the instrument or guidetube that is sufficient to cause friction to prevent adjacent vertebraefrom moving. The cable or cables may run through a large, central holein each vertebra or may run through smaller holes near the vertebra'souter circumference. Alternatively, the drive element of one or moremotors that move one or more control cables may be soft-locked inposition (e.g., by servocontrol) to hold the cables in position andthereby prevent instrument or guide tube movement, thus locking thevertebrae in place. Keeping a motor drive element in place may be doneto effectively keep other movable instrument and guide tube componentsin place as well. It should be understood that the stiffness underservocontrol, although effective, is generally less than the stiffnessthat may be obtained with braking placed directly on joints, such as thebraking used to keep passive setup joints in place. Cable stiffnessgenerally dominates because it is generally less than servosystem orbraked joint stiffness.

In some situations, the compliance of the flexible segment may becontinuously varied between flaccid and rigid states. For example,locking cable tension can be increased to increase stiffness but withoutlocking the flexible segment in a rigid state. Such intermediatecompliance may allow for telesurgical operation while reducing tissuetrauma that may occur due to movements caused by reactive forces fromthe surgical site. Suitable bend sensors incorporated into the flexiblesegment allow the telesurgical system to determine instrument and/orguide tube position as it bends. U.S. Patent Application Pub. No. US2006/0013523 (Childers et al.), which is incorporated by reference,discloses a fiber optic position shape sensing device and method. U.S.patent application Ser. No. 11/491,384 (Larkin et al.), which isincorporated by reference, discloses fiber optic bend sensors (e.g.,fiber Bragg gratings) used in the control of such segments and flexibledevices.

A surgeon's inputs to control aspects of the minimally invasive surgicalinstrument assemblies, instruments, and end effectors as describedherein are generally done using an intuitive, camera referenced controlinterface. For example, the da Vinci® Surgical System includes aSurgeon's console with such a control interface, which may be modifiedto control aspects described herein. The surgeon manipulates one or moremaster manual input mechanisms having, e.g., 6 DOFs to control the slaveinstrument assembly and instrument. The input mechanisms include afinger-operated grasper to control one or more end effector DOFs (e.g.,closing grasping jaws). Intuitive control is provided by orienting therelative positions of the end effectors and the endoscopic imagingsystem with the positions of the surgeon's input mechanisms and imageoutput display. This orientation allows the surgeon to manipulate theinput mechanisms and end effector controls as if viewing the surgicalwork site in substantially true presence. This teleoperation truepresence means that the surgeon views an image from a perspective thatappears to be that of an operator directly viewing and working at thesurgical site. U.S. Pat. No. 6,671,581 (Niemeyer et al.), which isincorporated by reference, contains further information on camerareferenced control in a minimally invasive surgical apparatus.

FIG. 1 is a diagrammatic view of a minimally invasive surgicalinstrument 1 and its motion. As shown in FIG. 1, surgical instrument 1is a straight, rigid instrument that is inserted via a small incision 2into a body cavity (e.g., the abdominal cavity) or lumen 3. Incision 2is made in a relatively thin body wall tissue structure 4, such as theabdominal wall. A surgeon moves instrument 1 either by hand (e.g., byoperating a conventional laparoscopic instrument) or by roboticteleoperation (e.g., using Intuitive Surgical, Inc.'s da Vinci® SurgicalSystem). Since instrument 1 is straight, its movement is partiallyconstrained by incision 2. Instrument 1 may be translated in thedirection of its longitudinal axis (inserted or withdrawn) and may berotated around its longitudinal axis. Instrument 1 also pivots at acenter point 5, which is approximately at incision 2, to sweep an endeffector 7 through a volume 6. An optional wrist mechanism (not shown)at the distal end of instrument 1 may be used to control end effector7's orientation. In some situations, however, an intermediate tissuestructure (e.g., an organ or vessel, a thick tissue wall 4, a curvingbody lumen wall, etc.) prevents instrument 1 from pivoting around itscenter point 5 at incision 2 in some or all directions, which prevents asurgeon from reaching a desired surgical site.

If a minimally invasive surgical instrument is designed to bend betweenthe position at which it enters the patient and the surgical site, thenthe intermediate tissue structure does not constrain positioning of theinstrument's end effector. Such bending may be done in two ways. First,two or more long, rigid body segments are each coupled together by ajoint. Second, a flexible mechanism as described above is used. Theposition of the rigid body segment(s) and the flexible mechanism areactively controlled to position and orient the end effector at theinstrument's distal end.

FIG. 2A is a diagrammatic view of another minimally invasive surgicalinstrument 10 and its motion in accordance with aspects of theinvention. As shown in FIG. 2A, instrument 10 includes an illustrativeproximal instrument body segment 10 a and an illustrative distalinstrument body segment 10 b. In some aspects, more than two bodysegments may be used. As depicted, both proximal and distal bodysegments 10 a,10 b are straight and rigid. Alternatively, one or bothbody segments 10 a,10 b could be curved for a particular path or task.The two body segments 10 a,10 b are coupled at a joint 11 that allowsdistal body segment 10 b to move. In some aspects joint 11 allowssegment 10 b to move with a single DOF with reference to segment 10 a,and in other aspects joint 11 allows segment 10 b to move with two DOFswith reference to segment 10 a segment. Instrument 10 can be translatedalong its longitudinal (insertion) axis. In some aspects, proximalsegment 10 can be rolled around its longitudinal axis. Accordingly, endeffector 7 positioned at the distal end of distal body segment 10 b canbe positioned within a volume 12. In some aspects joint 11 provides asingle DOF, and so end effector 7 sweeps along a planar curve thatrotates as proximal segment 10 a rotates around its longitudinal axis.In some aspects joint 11 provides two DOFs, and so end effector 7 sweepsalong a curved surface. The height of volume 12 depends on the amount ofinstrument 10's insertion. Volume 12 is shown as an illustrativecylinder with concave/convex ends. Other volume shapes are possible,depending on the segments and joint motions at instrument 10's distalend. For example, in some aspects distal segment 10 b may be displacedby an angle θ from segment 10 a's longitudinal axis that is larger than90 degrees (this bending back on itself is termed “retroflexive”). Anoptional wrist mechanism (not shown) may be used to change end effector7's orientation.

Unlike instrument 1 shown in FIG. 1, instrument 10 is not constrained bya pivot point at a body wall because joint 11 is located deep within thepatient. Therefore, instrument 10 can be inserted into a patient pastintermediate tissue structures 13 that would otherwise constraininstrument 1's motion (e.g., the esophagus, if gastric surgery is to beperformed) or that cannot be disturbed (e.g., brain tissues ifneurosurgery is to be performed). Accordingly, aspects of surgicalinstrument 10 allow a surgeon to reach tissue that cannot be reached oroperated upon by using instrument 1. Removing the constraint that thesurgical instrument segments be straight and rigid allows even moresurgical access to tissue structures.

Instead of using only rigid instrument body segments, one or moreflexible segments may be used. FIG. 2B is a diagrammatic view of anotherminimally invasive surgical instrument 15 and its motion in accordancewith aspects of the invention. As shown in FIG. 2B, surgical instrument15 has a proximal instrument body segment 15 a and a distal instrumentbody segment 15 b. Instead of being straight and rigid, distal bodysegment 15 b is flexible as described above. In some aspects flexibledistal segment 15 b is coupled to straight (or, alternatively, curved),rigid proximal segment 15 a at an intermediate position 15 c. In otheraspects, both proximal instrument body segment 15 a and distalinstrument body segment 15 b are flexible, and intermediate instrumentbody position 15 c is illustrative of the position at which the twosegments are jointed. Instrument body segment 15 b is shown with anillustrative simple curve. In other aspects as discussed below bodysegment 15 b may be a compound curve in either two or three dimensions.

During surgery, instrument 15 positions end effector 7 at variouspositions in illustrative volume 16. Instrument body segment 15 aremains constrained by intermediate tissue structures 13 and instrumentbody segment 15 b flexes. Distal segment 15 b's length and bend radiusdetermines if instrument 15 can operate retroflexively. It can be seenthat compound bending of instrument body segment 15 b will allow asurgeon to maneuver around another intermediate tissue structure 13 awithin volume 16. (A similar action may be performed if instrument 10(FIG. 2A) has two or more distal segments.) An optional wrist mechanism(not shown) is used to control end effector 7's orientation. Inaddition, in some aspects if flexible segment 15 b is designed totransmit roll, then end effector 7 can be rolled by rolling instrument15 (either with or without a wrist mechanism).

The surgical instruments 10 and 15 illustrated in FIGS. 2A and 2B arenot limited to single instruments. The architectures illustrated byinstruments 10 and 15 may be applied to assemblies that combine one ormore of various guide tubes, surgical instruments, and guide probes suchas those described below. And, one or more imaging systems (endoscopes)may be added to such instruments and instrument assemblies. The aspectsdescribed below in association with the figures are illustrative ofaspects generally described in FIGS. 2A and 2B. Therefore, aspects ofthe invention provide multiple telemanipulated surgical instruments,each surgical instrument working independently of the other and eachhaving an end effector with at least six actively controlled DOFs inCartesian space (i.e., surge, heave, sway, roll, pitch, yaw), via asingle entry port in a patient. Further, aspects of the inventionprovide multiple telemanipulated surgical instruments, each surgicalinstrument working independently of the other and each having an endeffector with at least six actively controlled DOFs in Cartesian space(i.e., surge, heave, sway, roll, pitch, yaw), via a single entry port ina patient and past intermediate tissue that restricts lateral movementof a rigid instrument body. The end effectors' six DOFs in Cartesianspace are in addition to DOFs provided by, e.g., moving a guide tubethrough which the instruments extend to reach a surgical site.

Surgical Instrument Assemblies

FIG. 3 is a schematic view of a minimally invasive surgical instrument300. Surgical instrument 300 is typically inserted into a patient's bodyvia a cannula 302 or via a natural orifice or incision. An end effector304 is mounted at the end of instrument 300. In some instancesinstrument 300's body is passively flexible along its entire length in amanner similar to existing flexible minimally invasive surgicalinstruments. For example, a cable axially runs through a helical woundwire coil and outer sheath that protects the cable, and the cabletranslates within the coil to operate the end effector (e.g., a “Bowden”cable). As another example, a series of small, annular vertebra segmentsmay be used to make instrument 300 flexible. In other instances,instrument 300's body may be separated into a proximal segment 306 and adistal segment 308. Each instrument body segment 306,308 may be rigid,passively flexible, or actively flexible. Flexible segments may be maderigid (“rigidizable” or “lockable”) in various straight or curvedpositions. As shown in FIG. 3, for example, proximal segment 306 may beinherently or lockably rigid, and distal segment 308 may be passively oractively flexible. In other instances, both proximal and distal segments306,308 (essentially the entire segment of instrument 302 that is insidethe patient's body) may be passively or actively flexible andrigidizable in various combinations.

The surgical instrument 300 shown in FIG. 3 provides various degrees offreedom for end effector 304. To control end effector 304's position,for example, a combination of instrument 300 insertion and distalsegment 308 bending is specified. To control end effector 304'sorientation, a combination of instrument 300 roll and distal segment 308bending is specified. Accordingly, if distal segment 308 can only beplaced in a simple curve (as illustrated by alternate position 310),then 4 DOFs are available. If end effector 304 position is specified,then end effector 304 pitch and yaw is a function of the position. Ifend effector 304 orientation is specified, then the heave and swayposition is a function of the orientation. Therefore, a distal wristmechanism is added to control end effector 304's orientation so thatboth position and orientation may be specified. If distal segment 308can be placed in a compound curve (as illustrated by alternate position312), then 6 DOFs are available, and end effector 304's position andorientation may be specified. Even though end effector 304's positionand orientation may be independently specified in such a 6 DOFinstrument, a distal wrist mechanism may be added to provide enhancedcontrol over end effector 304's orientation. This enhanced controlallows, e.g., a pitch and yaw displacement that is larger than providedby the various poses that distal segment 308 can assume, pitch and yawdisplacement while distal segment 308 remains in a particular pose, andpitch and yaw displacement in surgical situations where tissueconstrains the shape of distal segment 308's pose.

FIG. 4 is a schematic view that illustrates aspects of a minimallyinvasive surgical instrument assembly 400. Instrument assembly 400includes a surgical instrument 402, which may be similar to surgicalinstrument 300 as described with reference to FIG. 3, and a guide tube404. Guide tube 404 has at least one longitudinal channel 406, which maybe fully or partially enclosed, that runs from proximal end 408 todistal end 410. Surgical instrument 402 runs through channel 406 and maybe, for example, snap-fitted into a non-rotating socket to maintainposition within guide tube 404. Guide tube 404 may have other channels(not shown) through which, e.g., irrigation or suction may be providedto a surgical site, in addition to channels associated with activecontrol mechanisms (e.g., cables for steering or locking). End effector412 is coupled to the distal end of surgical instrument 402. Instrumentassembly 400 is inserted into a patient via cannula 414 or via naturalorifice or incision. In some instances, a cannula-type guide may be usedto assist insertion via natural orifice. Cannula 414 and suchcannula-type guides may be straight or curved to facilitate insertion(e.g., for laryngeal surgery). Surgical instrument assembly 400's crosssection may be circular or other shape (e.g., elliptical, roundedpolygon). Various combinations of surgical instrument 402 and guide tube404 may be rigid, passively flexible, and actively flexible, as well asvariably compliant and/or lockable, as described above. In someinstances, an optional endoscopic imaging system (not shown) may be atthe distal end of guide tube 404.

Just as some or all of surgical instrument 300 (FIG. 3) may be flexed tomove its end effector to various positions and orientations, surgicalinstrument assembly 400 may be similarly flexed to move end effector 412to various positions and orientations. Distal end segment 416, or theentire length of instrument assembly 400, may be actively flexed toheave and/or sway end effector 412. Combinations of bending and rollingmay also be used to displace end effector 412. Compound bends mayprevent end effector 412 from pitching and/or yawing during lateraltranslations as described above. Alternate positions 418 and 420illustrate these active flexings. In accordance with an aspect of theinvention, in some instances distal segment 416 of guide tube 404provides small, wrist-like pitch and yaw orientation for end effector412. Other segments of instrument assembly 400 provide end effector rolland position.

Surgical instrument assembly 400 potentially provides more DOFs, someredundant, for end effector 412 than surgical instrument 300 providesfor end effector 304, as described with reference to FIG. 3. As shown inFIG. 4, in some aspects surgical instrument 402 may rotate within guidetube 404, and/or guide tube 404 may rotate within cannula 414 (or thenatural orifice), to cause end effector 412 to be displaced in rollaround instrument assembly 400's longitudinal axis. Instrument 402 maytranslate within guide tube 404, and/or guide tube 404 may translatewithin cannula 414, to cause end effector 412 to be displaced (surged)along instrument assembly 400's longitudinal axis. Alternatively,instrument 402 is held in position within guide tube 404 as describedbelow. The lateral bending force that the guide tube's distal segment416 exerts on the surgical instrument's distal end 402 is sufficientlystrong to allow end effector 412 to perform its surgical task. In someinstances, end effector 412 may be coupled to the distal end of surgicalinstrument 402 via a wrist mechanism that provides one or moreadditional DOFs (e.g., roll, pitch, yaw).

FIG. 4 also illustrates that when a guide tube bends, the bend must notbind operation of an instrument or another guide tube that runs insideit. For instance, guide tube 404 must not bend in such a way that acable operating end effector 412 is frictionally bound or permanentlykinked. In some aspects the radius of curvature is mechanically limitedby, e.g., the structure of the individual vertebrae that make up theflexible guide tube. In other aspects the radius of curvature is limitedby a control system, described below, to provide, e.g., a smootherbehavior during actuation. Further, in some aspects cables for innerinstruments or guide tubes must not shift to a shorter path betweentheir proximal and distal ends so that the components they control arenot affected as the guide tube bends (such shifting may be compensatedfor by using distal bend/shape sensors and a control system thatmaintains proper cable length). Cable path lengths may be stabilized byusing sheathes (e.g. Bowden cables) for cables running through thecenter of the flexible joints or by routing cables through the jointperipheries as described below for virtual pivot point joints.

In some instances surgical instrument 402 is removable and may bereplaced with a different surgical instrument that has a structuresimilar to instrument 402 but a different end effector so as to performa different surgical task. Accordingly, a single guide tube 404 may beused to provide wrist-like DOFs for one or more interchangeable surgicalinstruments 402. In some instances the surgical instruments may beinterchanged while guide tube 404 remains in the patient. Suchinterchangeability is described in more detail below. The guide tubeallows the newly inserted instrument to be positioned directly at thesurgical site, regardless of the trajectory. And, one guide tube 404 maybe withdrawn and replaced with another during surgery, either with orwithout an instrument 402 fully or partially inserted. Since some or allof the controllable DOFs are in the guide tube, in some aspects theinstrument can be inexpensively made and therefore disposable, and theguide tube can be made sterilizable and reusable.

FIGS. 4A and 4B are diagrammatic perspective views that illustrateaspects of a removable instrument that is held in place within guidetube 440. The distal end 442 of guide tube 440 has an opening 444 thoughwhich the distal end of the instrument passes. Opening 444 is optionallymade non-round to prevent the instrument from rolling within guide tube440. An optional fitting 446 (e.g., a spring that snaps into a detentetc.) holds the instrument's end effector 448 in position to keep theinstrument from translating through the guide tube. A round opening 444allows the instrument to roll while fitting 446 keeps the instrumentfrom translating. When the fitting 446 releases the instrument (e.g.,when sufficient pulling force is applied), the instrument may bewithdrawn from the guide tube. Distal end 442 may be a wrist mechanismfor the instrument's end effector in some aspects. The roll preventionconfiguration and the fitting are illustratively shown at the distal endof the guide tube but may be placed at various positions (e.g., at theinsertion end of the guide tube). The roll prevention configuration andthe fitting can be used in the various aspects described below for otherinstrument and guide tube combinations, with the understanding that theroll preventing configuration and the fitting will remove a redundantinsertion DOF and/or a redundant roll DOF.

Instrument assembly 400 may be inserted in a rigidized or locked state,or it may be actively steered during insertion in order to reach atarget surgical site. In some aspects instrument 402 and guide tube 404are alternatively coaxially advanced. For example, instrument 402 isactively steered part way along the trajectory to the surgical site andthen locked (only the distal section of the instrument (or guide tube)need be actively steerable; the more proximal sections may be passive ormay use curve propagation as the instrument (or guide tube) advances).Curve propagation is disclosed in, e.g., Ikuta, K. et al., “Shape memoryalloy servo actuator system with electric resistance feedback andapplication for active endoscope,” 1988 IEEE International Conference onRobotics and Automation, Apr. 24-29, 1988, Vol. 1, pages 427-430, whichis incorporated by reference. Guide tube 404 is then passively advancedto the distal end of instrument 402 and locked to support furtheradvancement of instrument 402. The coaxial alternating advancing andlocking continues until the surgical site is reached along the desiredtrajectory. Alternatively, guide tube 404 is actively steerable andlockable, and instrument 402 is passively advanced and locked withinguide tube until the surgical site is reached. If both surgicalinstrument 402 and guide tube 404 are actively steerable, then they may“leapfrog” each other as they coaxially advance and lock along thetrajectory to the surgical site. Such coaxial insertion may also be usedwith any combination of two or more instruments and guide tubesdescribed herein.

FIG. 5 is a schematic view that illustrates aspects of a secondminimally invasive surgical instrument assembly 500. Surgical instrumentassembly 500 illustrates that two or more surgical instruments 502 a,502b may be surrounded by a single guide tube 504. Surgical instruments 502a,502 b may run longitudinally through guide tube 504 in a singlechannel 506. Or, surgical instruments 502 a,502 b may each run throughguide tube 504 in unique, individual channels 506 a,506 b. End effectors508 a,508 b are each coupled to the distal ends of instruments 502 a,502b. Instrument assembly 500 is inserted via cannula 510 and as describedabove. Instrument assembly 500's cross section may be circular,elliptical, or other shape (e.g., rounded rectangle or other polygon).Various combinations of surgical instruments 502 a,502 b and guide tube504 may be rigid, passively flexible, and actively flexible, as well aslockable, as described above. An illustrative optional imaging system511 (e.g., one or more image capture chips with associated optics andelectronics) is positioned at the distal end of guide tube 504. Theimaging system 511 has a field of view that may be used to assistadvancing guide tube 504 and that allows a surgeon to view end effectors508 a,508 b working at a surgical site.

Surgical instrument assembly 500 operates in a manner similar to that ofsurgical instrument assembly 400 (FIG. 4), except that it isillustrative of aspects in which two or more surgical instruments extendthrough a single guide tube from a proximal to a distal end.Accordingly, the descriptions above of additional channels, active andpassive flexibility, locking/rigidizing, various DOFs, the optional useof wrist mechanisms, instrument interchangeability, alternating coaxialadvancing, and cannulas apply to instrument assembly 500. Distal endsegment and entire assembly flexibility are illustrated by alternateposition lines 512 and 514, similar to those shown in the precedingfigures as described above. Compound bending of guide tube 504 providesat least 6 DOFs for end effectors 508 a,508 b as described above.Alternating coaxial advancement may be done as described above. Variousways of such advancing are possible. For example, in some aspects bothinstruments may be used and the guide tube slides over both instruments;in other aspects first one instrument is advanced and locked, then theguide tube is advanced and locked, then the other instrument is advancedand locked, etc.

FIG. 6 is a schematic view that illustrates aspects of a third minimallyinvasive surgical instrument assembly 600. Surgical instrument assembly600 operates in a manner similar to that of surgical instrument assembly400 (FIG. 4), except that it is illustrative of aspects in which asurgical instrument 602's actively flexible distal segment 604 extendsbeyond the distal end of guide tube 606. Active flexibility of guidetube 606's distal end segment 608 and/or of the entire guide tube 606are illustrated by alternate position lines 610 and 612. Activeflexibility of instrument 602's distal segment 604 moves end effector614 to illustrative alternate position 616. Accordingly, end effector614 experiences wrist-like DOFs (e.g., roll, pitch, yaw) from themovement of instrument 602's distal segment 604, from the movement ofguide tube 606's distal segment 608, and/or from a combination ofmovements by distal segments 604,608. Thus, instrument assembly 600illustrates aspects in which combinations of instruments and guide tubesprovide redundant position and orientation DOFs for end effector 614.The descriptions above of additional channels, active and passiveflexibility, locking/rigidizing, various degrees of freedom, increasedlateral force application and stiffness, the optional use of wristmechanisms and imaging systems, instrument interchangeability,alternating coaxial advancing, and cannulas apply to instrument assembly600.

FIG. 7 is a schematic view that illustrates aspects of a fourthminimally invasive surgical instrument assembly 700. As shown in FIG. 7,surgical instrument 702 extends through primary guide tube 704 alonginstrument assembly 700's longitudinal axis. In addition, primary guidetube 704 extends through secondary guide tube 706 along the longitudinalaxis. In some instances surgical instrument assembly 700 is inserted viaa cannula 708. End effector 710 is coupled to the distal end of surgicalinstrument 702 so that it extends just beyond primary guide tube 704'sdistal end.

End effector 710's redundant DOFs, other than the inherent one or moreDOFs associated with its specific task (e.g., gripping), are provided invarious ways. Surgical instrument 702 may rotate within primary guidetube 704, and/or primary guide tube 704 may rotate within secondaryguide tube 706, and/or secondary guide tube 706 may rotate withincannula 708 (or a natural orifice or incision), which causes endeffector 710 to be displaced in roll around instrument assembly 700'slongitudinal axis. Surgical instrument 702 may translate within primaryguide tube 704, and/or primary guide tube 704 may translate withinsecondary guide tube 706, and/or secondary guide tube 706 may translatewithin cannula 708, to displace (surge) end effector 710 alonginstrument assembly 700's longitudinal axis.

As shown in FIG. 7, an actively flexible distal segment 712 of primaryguide tube 704 extends beyond secondary guide tube 706's distal end.Distal segment 712 may cause end effector 710 to be heaved and/or swayed(with incidental pitch and yaw as discussed above), adding one or twoadditional degrees of freedom as illustrated by alternate position 714.Similarly, an actively flexible distal segment 716 of secondary guidetube 706, or the entire secondary guide tube 706, may cause end effector710 to be heaved and/or swayed, adding one or two more degrees offreedom as illustrated by alternate positions 718 and 720. Sinceinstrument assembly 700 provides various combinations of roll, heave,and sway displacements for end effector 710, a wrist-type mechanism maynot be required to couple end effector 710 to surgical instrument 702,although such a mechanism may be used to provide an additional one ormore degrees of freedom (e.g., roll, pitch, yaw).

As indicated by the alternate position lines in FIG. 7, the primary andsecondary guide tubes can maneuver end effector 710 with variouscombinations of simple and compound bends. In one illustrativeembodiment, secondary guide tube 702's active flexibility is used forrelatively large movements of end effector 710, and primary guide tubedistal segment 712's active flexibility is used for relatively small,wrist-type movements of end effector 710. The amount of such motiondepends on the distance that distal segment 712 extends beyond secondaryguide tube 706, and so may provide motion similar to that described inFIG. 2B.

In some instances surgical instrument 702 may extend beyond primaryguide tube 704 as described in FIG. 6. The descriptions above ofadditional channels, active and passive flexibility, locking/rigidizing,various DOFs, increased lateral force application and stiffness,instrument interchangeability, alternating coaxial advancing, andcannulas apply to instrument assembly 700. In addition, since secondaryguide tube 706 has an even greater outer diameter than primary guidetube 704, actuation and locking mechanisms for secondary guide tube 706may provide an increased lateral force and stiffness against reactionforces than either instrument 702 or primary guide tube 704 may providealone or together.

FIG. 8 is a schematic view that illustrates aspects of a fifth minimallyinvasive surgical instrument assembly 800. Surgical instrument assembly800 illustrates that two or more primary guide tubes 802 a,802 b may besurrounded by a single secondary guide tube 804. An illustrativesurgical instrument 806 a,806 b runs though each of primary guide tubes802 a,802 b. The primary guide tubes 802 a,802 b have an architecturegenerally similar to surgical instrument assembly 400 (FIG. 4). In someinstances, however, one or more primary guide tubes 802 may have anarchitecture similar to surgical instrument assembly 500 (FIG. 5) orsurgical instrument assembly 600 (FIG. 6). Active flexibility of thedistal segments of primary guide tubes 802 a,802 b that extend beyondthe distal end of secondary guide tube 804 are illustrated by alternateposition lines 808 a,808 b. The distal segments of primary guide tubes802 a,802 b can move end effectors 809 a,809 b adjacent one another atvarious positions at a surgical site within a patient so as to performvarious surgical tasks. Various active flexibilities of secondary guidetube 804 are illustrated by alternate position lines 810 a,810 b. Thedescriptions above of additional channels, active and passiveflexibility, locking/rigidizing, various DOFs, increased lateral forceapplication and stiffness, the optional use of wrist mechanisms,instrument interchangeability, alternating coaxial advancing, andcannulas apply to instrument assembly 800.

In some instances an endoscopic imaging system 812, representedschematically by a dashed box, is positioned at secondary guide tube804's distal end. Imaging system 812 may be mono- or stereoscopic asdescribed above and may have a viewing angle aligned with or angled(e.g., 30 degrees) from instrument assembly 800's longitudinal axis. Insome instances imaging system 812 is positioned between primary guidetubes 802 a,802 b. In other instances imaging system 812 is positionedabove, below, or to the side of primary guide tubes 802 a,802 b to makesecondary guide tube 804's cross section more compact (e.g., onestereoscopic lens window above and one below the primary guide tubes 802a,802 b; camera referenced control for this configuration is madepossible if the primary guide tubes bend out and then inwards towardsthe surgical site roughly coplanar with the interpupillary axis).

FIG. 9 is a schematic view that illustrates aspects of a sixth minimallyinvasive surgical instrument assembly 900. Instrument assembly 900 issimilar to instrument assembly 800 (FIG. 8), except that an illustrativeadditional surgical instrument 902 extends through secondary guide tube904, but surgical instrument 902 is not surrounded by a primary guidetube. Accordingly, the relationship between surgical instrument 902 andsecondary guide tube 904 is similar to that described between thesurgical instruments and guide tubes as shown in FIGS. 4 and 6. Therelationship between the primary guide tube 906 a,906 b and instrument908 a,908 b assemblies is similar to that described for aspectsillustrated by FIGS. 7 and 8. Instrument assembly 900 is illustrative ofa secondary guide tube through which extend various combinations of oneor more primary guide tube and instrument assemblies as well as one ormore instruments without guide tubes.

In some instances surgical instrument 902 is rigid or passively flexibleand its end effector 910 is used to grasp and pull tissue to assist thesurgical tasks that end effectors 912 a,912 b at the ends of instruments908 a,908 b perform. Although rigid or passively flexible, instrument902 is capable of pulling with considerable force. In other instancessurgical instrument may perform other functions, such as retraction,irrigation, suction, etc. Further, if an endoscopic imaging system isplaced at the distal end of secondary guide tube 904, as illustrated byinstrument assembly 800 (FIG. 8), then instrument 902 may be used toservice (e.g., clean with a jet of fluid) the imaging system'swindow(s).

In still other instances, as mentioned above, surgical instrument 902'sdistal end is actively flexible, and end effector 910 is replaced by anendoscopic imaging system 914 as shown in FIG. 9A. In these instances adistal imaging device may be coupled to the actively flexible end ofsurgical instrument 902 with a wrist-type mechanism 916 that provides atleast a DOF in pitch. Such an architecture allows the image sensingdevice to be moved out from between the distal ends of primary guidetubes 906 a,906 b and then the viewing angle is pitched (and/or yawed)to align the center of the visual field with the area at which the endeffectors 912 a,912 b are working. This architecture enables a surgeonto work, at a surgical site via a single entry port into the body, withtwo independently actuated surgical end effectors and an endoscopicimaging system that is independent of the surgical instruments. Anotherbenefit of the independently controlled imaging system illustrated inFIG. 9A is tissue retraction, as shown and described more fully withreference to FIG. 17A below.

In accordance with aspects described above, one or more surgicalinstruments exit at the distal end of an guide tube, which may be a flatface or other shape, square or inclined to the assembly's longitudinalaxis. In accordance with other aspects, one or more surgical instrumentsexit from the side of a guide tube. FIG. 10 is a schematic view thatillustrates such aspects in a seventh minimally invasive surgicalassembly 1000.

As shown in FIG. 10, two surgical instruments 1002 a,1002 b(illustrative of two or more instruments) extend longitudinally throughguide tube 1004. Instruments 1002 a,1002 b exit guide tube 1004's distalsegment 1006 via side exit ports 1008 a,1008 b instead of at guide tube1004's extreme distal end. The side exit ports 1008 a,1008 b may beoriented to be generally opposite each other (i.e., displacedapproximately 180 degrees from each other) or they may be separated by alesser angle (e.g., 120 degrees). And, the side exit ports may havevarious angular orientations around distal segment 1006 in aspects inwhich more than two exit ports are used for one, two, or more than twoinstruments 1002. In one aspect one side exit port is farther from guidetube 104's distal tip than another side exit port. Instrument 1002 a'sdistal segment 1010 a and instrument 1002 b's distal segment 1010 b areeach independently actively flexible so as to move end effectors 1012a,1012 b for work at a surgical site. Various combinations of simple orcompound bending with instrument roll and insertion, along with optionalwrist mechanisms, provide the required end effector DOFs. An endoscopicimaging system 1014 is positioned at the distal end of guide tube 1004.Imaging system 1014's viewing angle may be aligned with instrumentassembly 1000's longitudinal axis, or the viewing angle may be angled(e.g., 30 degrees) from the longitudinal axis. In some aspects theviewing angle may be actively changed during a surgical procedure using,e.g., one or move movable reflecting surfaces (mirrors, prisms). Thedescriptions above of additional channels, active and passiveflexibility, locking/rigidizing, various DOFS, increased lateral forceand stiffness, the optional use of wrist mechanisms, instrumentinterchangeability, and cannulas apply to instrument assembly 1000.

Surgical assembly 1000 is inserted into a patient via incision ornatural orifice, in some instances through cannula 1016 or a similarguiding structure as described above. As guide tube 1004 is inserted, insome instances surgical instruments 1002 a,1002 b are either fully orpartly retracted so that they do not extend beyond openings 1008 a,1008b as guide tube 1004 advances towards a surgical site. Images fromimaging system 1014 may assist advancement. Once guide tube 1004 is inposition at the surgical site, instruments 1002 a,1002 b may then beinserted and/or advanced within guide tube 1004 to reach the surgicalsite. Guide tube 1004 may be actively flexed during a surgical procedureto provide gross movements at the surgical site while instrument distalsegments 1010 a,1010 b perform fine movements to complete the surgicaltask, as illustrated by alternate position lines 1018 a,1018 b. Thesurgeon views images from imaging system 1014 while performing surgicaltasks with end effectors 1012 a,1012 b. Since the surgeon cannot seeimages from imaging system 1014 of distal segments 1010 a,1010 b as theyexit side ports 1008 a,1008 b, in some aspects a control system,described below, controls distal segments 1010 a,1010 b as they exitfrom guide tube 1004 so that they curve to meet in front of imagingsystem 1014. In other aspects, a luminal space is mapped as describedbelow, and the control system uses the mapping data to guide the endeffectors into imaging system 1014's field of view. In still otheraspects the distal end of the guide tube may be moved, e.g., to the leftfrom a known space, thereby allowing the right instrument to be insertedinto the “safe” space to the right of the guide tube. Then, likewise,the distal end of guide tube is moved to the right and the leftinstrument is moved into the “safe” space to the left of the guide tube.For aspects in which the distal end of the guide tube moves upwardindependently of the part of the guide tube at which the instrumentsexit, the instruments may be similarly inserted into the “safe” spaceunderneath the upwardly displaced distal end of the guide tube. Forwithdrawal, or subsequent large repositioning, instruments 1002 a,1002 bmay be withdrawn through side exit ports 1008 a,1008 b, either partiallyinto or entirely from guide tube 1004.

FIG. 11 is a schematic view that illustrates aspects of an eighthminimally invasive surgical assembly 1100. As shown in FIG. 11, surgicalinstrument 1102 a extends through primary guide tube 1104 a along itslongitudinal axis. Likewise, surgical instrument 1102 b extends throughprimary guide tube 1104 b along its longitudinal axis. End effectors1106 a,1106 b are coupled to the distal ends of instruments 1102 a,1102b. Primary guide tubes 1104 a,1104 b extend longitudinally throughsecondary guide tube 1108. In a manner similar to the way surgicalinstruments 1002 a,1002 b exit side ports 1008 a,1008 b of guide tube1004's distal segment 1106, primary guide tubes 1104 a,1104 b exit sideports 1110 a,111 b of secondary guide tube 1108. The distal segments1112 a,1112 b of primary guide tubes 1104 a,1104 b actively flex to moveend effectors 1106 a,1106 b, as illustrated by alternate position lines1114 a,1114 b. An endoscopic imaging system 1116 is positioned atsecondary guide tube 1108's distal end. The descriptions above ofadditional channels, active and passive flexibility, locking/rigidizing,various DOFs, increased lateral force application and stiffness, theoptional use of wrist mechanisms, instrument interchangeability,cannulas, and endoscopic imaging systems apply to instrument assembly1100.

Instrument assembly 1100 operates in a manner similar to instrumentassembly 1000 (FIG. 10). The principal difference between the twoaspects is the use of both secondary and primary guide tubes in assembly1100. The relationship between instrument assemblies 1100 and 1000 istherefore akin to the relationship between instrument assemblies 800(FIG. 8) and 500 (FIG. 5). The descriptions above of insertion, full orpartial instrument retraction during insertion and repositioning, use ofthe imaging system, use of primary and secondary guide tubes, andcontrolled extension of instruments apply to aspects of instrumentassembly 1100.

FIGS. 11A and 11B are diagrammatic end views of surgical instrumentassemblies, and they illustrate that a side-exit assembly such asassemblies 1000 (FIG. 10) and 1100 (FIG. 11) may be used to reduce theoverall cross-sectional area of a guide tube or secondary guide tube.FIG. 11A is an illustrative view of an assembly, such as assembly 800(the circular cross-sectional shape is merely illustrative), in whichinstrument/guide tube combinations 802 a,806 a and 802 b,806 b exit fromthe distal end of a guide tube or secondary guide tube. In thisillustrative example, imaging system 812 is a stereoscopic imagingsystem with an interpupillary distance 1120 between imaging ports and anillustrative illumination port 1122. As shown in FIG. 11B's illustrativeexample, the side-exit assembly's instrument/distal guide tube segmentcombinations 1102 a,1112 a and 1102 b,1112 b have the samecross-sectional dimensions as combinations 802 a,806 a and 802 b,806 bshown in FIG. 11A. And, illustrative stereoscopic imaging system 1116has the same interpupillary distance 1120 as imaging system 812 as shownin FIG. 11A. If the endoscopic image is captured and digitized at thedistal end of the guide tube, then the guide tube area proximal of theimage capture and digitizing components can be used for instruments andactuation instead of for optics (e.g., fiber bundles, rod lenses, etc.).Consequently, the oblong-shaped cross-sectional area of FIG. 11B'sside-exit guide tube is smaller than the cross-sectional area of FIG.11A's end-exit guide tube, and the imaging system's interpupillarydistance is the same. This reduced cross-sectional area may be anadvantage for, e.g., the size and location of an incision to be used,for the size of a particular natural orifice, or for the position ofintermediate tissue between the entry port and the surgical site. Suchan oblong cross-sectional shape can be used in other instrument assemblyguide tubes described herein.

FIG. 12 is a schematic view that illustrates aspects of a ninthminimally invasive surgical instrument assembly 1200. Instrumentassembly 1200 is similar to instrument assembly 1100, with an additionalsurgical instrument 1202 that extends from the distal end of secondaryguide tube 1204. Surgical instrument 1202 operates in a manner similarto surgical instrument 902 (FIG. 9), being in some aspects rigid and inothers passively or actively flexible as described above. And, endeffector 1206 may be replaced with an endoscopic imaging system asdescribed with reference to FIGS. 9 and 9A or FIGS. 17 and 17A so thatin some aspects instrument assembly 1200 has an independently operated,optionally wrist-mounted, endoscopic imaging system 1208 as illustratedin FIG. 12.

FIGS. 12A and 12B are diagrammatic views of embodiments that illustrateretroflexive positions in examples of side-exit guide tubes, similar toretroflexive movement for end-exit guide tubes discussed above. FIG. 12Aillustrates that in one aspect the side-exit instrument assembly 1220actively bends in a plane that is approximately coplanar with the sideexit ports 1222 a and 1222 b (yaw with reference to the visual fieldreference). FIG. 12B illustrates that in another aspect the side exitinstrument assembly 1230 actively bends in a plane that is approximatelyperpendicular to the side exit ports 1232 a and 1232 b (hidden) (pitchwith reference to the visual field reference). Assembly 1230's bendradius may be smaller than assembly 1220's bend radius, other dimensionsbeing substantially the same, due to the mechanical structure. In someaspects the side-exit instrument assembly may simultaneously yaw andpitch, and the assembly may yaw/pitch distally of the side exit ports.

FIGS. 13 and 14 are schematic views that illustrate tenth and eleventhaspects of minimally invasive surgical instrument assemblies 1300 (FIG.13) and 1400 (FIG. 1400). Surgical instrument assemblies 1300 and 1400combine aspects of surgical instrument assemblies illustrated in FIGS.3-12B and the associated descriptions. Specifically, instrument assembly1300 illustrates aspects in which one or more surgical instruments 1302exit the end of a distal segment 1304 of a guide tube 1306, and one ormore other surgical instruments 1308 exit from a side exit port 1310 atguide tube 1306's distal segment 1304. Likewise, instrument assembly1400 illustrates aspects in which one or more surgical instruments 1402run coaxially within one or more primary guide tubes 1404 that exit theend of a distal segment 1406 of a secondary guide tube 1408, and one ormore other surgical instruments 1410 run coaxially through one or moreother primary guide tubes 1412 that run coaxially within secondary guidetube 1408 and exit from one or more side exit ports 1414 at secondaryguide tube 1408's distal segment 1406. The descriptions above ofadditional channels, active and passive flexibility, locking/rigidizing,various DOFs, increased lateral force application and stiffness, theoptional use of wrist mechanisms, instrument interchangeability,cannulas, and endoscopic imaging systems apply to instrument assemblies1300 and 1400.

In many instances an instrument or instrument assembly as describedherein can be actively or passively positioned at a surgical site. Asufficiently flexible and maneuverable surgical instrument or surgicalinstrument assembly, such as those described herein, may be insertedwith one or more segments of the instrument or assembly functioning inaccordance with the insertion description below. In some instances,however, a guide probe can be used to initially define some or all ofthe trajectory between the entry port and the surgical site. The guideprobe may be maneuvered using, e.g., image data from an imaging systemat the guide probe's distal tip, real time image data from an externalimaging system (e.g., ultrasound, fluoroscopy, MRI), preoperative imagedata and computer analysis of likely trajectory, and variouscombinations of these data.

FIGS. 15A-15D are schematic views that illustrate aspects of inserting aflexible, steerable surgical instrument and surgical instrumentassembly, such as those described herein, by using a guide probe tomaneuver past intermediate tissue structures so as to reach a surgicalsite within a patient. Insertion may be via natural orifice or incision,either with or without using a cannula (not shown) as described above.As shown in FIG. 15A, a first intermediate tissue structure 1502prevents a surgical instrument or surgical instrument assembly fromoperating with a pivoting center point generally where it enters thebody, as shown in FIG. 1. In addition, a second intermediate tissuestructure 1504 exists between the position where the instrument orinstrument assembly passes the first intermediate tissue structure 1502and the target surgical site 1506, as shown in FIG. 2B. An instrument orinstrument assembly must be guided between and around the intermediatetissue structures to reach the surgical site.

As shown in FIG. 15A, in one aspect a guide probe 1508 is inserted pastfirst intermediate structure 1502 and is then actively maneuvered aroundsecond intermediate tissue structure 1504 to reach surgical site 1506 oranother desired position. The guide probe's primary function is toestablish a trajectory to the surgical site. An optional endoscopicimaging system 1509 may be mounted at guide probe 1508's distal tip. Insome aspects curve propagation as described above is used duringinsertion—curves initially formed by steering the distal end areautomatically propagated in a proximal direction on the guide probe asit is advanced towards the surgical site. Such curve propagation is doneusing, e.g., control systems as described below. Once at its desiredposition, guide probe 1508 is then rigidized so as to maintain its two-or three-dimensional curved shape. Next, a guide tube 1510 is insertedcoaxially over guide probe 1508, as shown in FIG. 15B. The guide tube1510 may be inserted to an intermediate position as shown, or it may beinserted and maneuvered to a position at surgical site 1506 as shown bythe alternate position lines. In some aspects, the guide probe and guidetube may be coaxially inserted, first one, then the other in a repeated,alternating way. Guide tube 1510 is illustrative of various primary andsecondary guide tubes, such as those shown in FIGS. 4-14. Once in adesired position, guide tube 1510 is then rigidized to maintain theshape defined by guide probe 1508, which is then withdrawn as shown inFIG. 15C. After the guide probe is withdrawn, a surgical instrument orsurgical instrument assembly 1512 may then be inserted through guidetube 1510 to reach surgical site 1506, as shown in FIG. 15D.

To facilitate guide tube insertion, in one aspect the guide probeextends beyond the coaxial guide tube by a distance sufficient to allowthe guide probe to enter a patient and reach the surgical site. Then,the guide probe is coaxially inserted. In an alternate aspect, aproximal portion (e.g., the transmission mechanism; see FIG. 27 for anillustrative view) of the guide probe is removable to allow the guidetube to be coaxially inserted over the guide probe.

As an illustrative example in accordance with surgical instrumentassembly 400 (FIG. 4), a guide probe is inserted, guide tube 404 isinserted over the guide probe, the guide probe is withdrawn, and thensurgical instrument 402 is inserted through guide tube 404. A similarprocedure can be used for guide tubes with multiple instrument channels,such as surgical instrument assembly 500 (FIG. 5). As anotherillustrative example in accordance with surgical instrument assembly 700(FIG. 7), a guide probe is inserted, primary guide tube 704 is insertedover the guide probe, secondary guide tube 706 is inserted over primaryguide tube 704, the guide probe is withdrawn, and instrument 702 isinserted through primary guide tube 704. Alternately, a guide probehaving a relatively larger outer diameter is inserted, secondary guidetube 706 is inserted over the guide probe, the guide probe is withdrawn,and primary guide tube 704 and instrument 706 are then inserted throughsecondary guide tube 706. A similar procedure can be used for secondaryguide tubes that have two or more primary guide tube and/or instrumentchannels. As yet another illustrative example, guide tube 1510 isanalogous to cannula 708, and instrument assembly 700 is insertedthrough guide tube 1510. Many variations in insertion order are possibleand are within the scope of the invention.

Referring again to FIG. 2A, it can be seen that a rigid distal segmentof a minimally invasive surgical instrument can also provide access to alarge volume deep within the body that is accessed through anintermediate tissue structure. Such mechanisms may be mechanicallysimpler to build and operate, and therefore may be less expensive andeasier to control than systems that use flexible technology. And, insome aspects such mechanisms may work back on themselves to provide acapability similar to the retroflexive bending described above.

FIG. 16 is a schematic view that illustrates aspects of a twelfthminimally invasive surgical instrument assembly 1600. As shown in FIG.16, two surgical instruments 1602 a,1602 b extend through channels 1604a,1604 b that extend longitudinally through rigid guide tube 1606. Insome aspects guide tube 1606 is straight and in others it is curved toaccommodate a particular insertion port (the instruments are similarlycurved to facilitate insertion). Guide tube 1606 may have variouscross-sectional shapes (e.g., circular, oval, rounded polygon), andvarious numbers of surgical instruments and channels may be used. Someoptional working channels may be used to provide supporting surgicalfunctions such as irrigation and suction. In some aspects an endoscopicimaging system (e.g., mono- or stereoscopic image capture or directview) is at guide tube 1606's distal end 1610. In one aspect guide tube1606 is inserted into a patient via an incision (e.g., approximately 2.0cm at the umbilicus) or natural orifice, either with or without the useof a cannula 1612 or similar guiding structure. In some aspects guidetube 1606 may rotate within cannula 1612:

As shown in FIG. 16, surgical instruments 1602 a and 1602 b function ina like manner, and many instrument functions (body roll, wristoperation, end effector operation, etc.) are similar to the surgicalinstruments used in the da Vinci® Surgical System (both 8 mm and 5 mminstrument body diameters). In other aspects the instruments mayfunction differently and/or have capabilities not embodied in da Vinci®Surgical System instruments (e.g., one instrument may be straight, oneinstrument may be jointed, one instrument may be flexible, etc.). In theillustrative aspect shown in FIG. 16, instrument 1602 a includes atransmission portion (not shown) at its proximal end, an elongatedinstrument body 1614, one of various surgical end effectors 1630, and asnake-like, two degree of freedom wrist mechanism 1626 that couples endeffector 1630 to instrument body 1614. As in the da Vinci® SurgicalSystems, in some aspects the transmission portion includes disks thatinterface with electrical actuators (e.g., servomotors) permanentlymounted on a support arm so that instruments may easily be changed.Other linkages such as matching gimbal plates and levers may be used totransfer actuating forces at the mechanical interface. Mechanicalmechanisms (e.g., gears, levers, gimbals) in the transmission portiontransfer the actuating forces from the disks to cables, wires, and/orcable, wire, and hypotube combinations that run through one or morechannels in instrument body 1614 (which may include one or morearticulated segments) to control wrist 1626 and end effector 1630movement. In some aspects, one or more disks and associated mechanismstransfer actuating forces that roll instrument body 1614 around itslongitudinal axis 1619 as shown. In some aspects the actuators for aparticular instrument are themselves mounted on a single linear actuatorthat moves instrument body 1614 longitudinally as shown within channel1604 a. The main segment of instrument body 1614 is a substantiallyrigid single tube, although in some aspects it may be slightlyresiliently flexible. This small flexibility allows a proximal bodysegment 1620 proximal of guide tube 1606 (i.e., outside the patient) beslightly flexed so that several instrument bodies can be spaced moreclosely within guide tube 1606 than their individual transmissionsegment housings would otherwise allow, like several cut flowers ofequal length being placed in a small-necked vase. This flexing isminimal (e.g., less than or equal to about a 5-degree bend angle in oneembodiment) and does not induce significant friction because the bendangle for the control cables and hypotubes inside the instrument body issmall.

As shown in FIG. 16, instruments 1602 a and 1602 b each include aproximal body segment that extends through the guide tube and at leastone distal body segment that is positioned beyond the guide tube'sdistal end. For example, instrument 1602 a includes proximal bodysegment 1620 that extends through guide tube 1606, a distal body segment1622 that is coupled to proximal body segment 1620 at a joint 1624, awrist mechanism 1626 that is coupled to distal body segment 1622 atanother joint 1628 (the coupling may include another, short distal bodysegment), and an end effector 1630. In some aspects the distal bodysegment 1622 and joints 1624 and 1628 function as a parallel motionmechanism 1632 in which the position of a distal reference frame at thedistal end of parallel motion mechanism 1632 may be changed with respectto a proximal reference frame at the proximal end of parallel motionmechanism 1632 without changing the orientation of the distal referenceframe.

FIG. 16A is a side elevation view of an embodiment of the distal end ofinstrument 1602 a, which includes parallel motion mechanism 1632, wristmechanism 1626, and end effector 1630. In this illustrative embodiment,parallel motion mechanism 1632's diameter is approximately 7 mm, andwrist 1626's diameter is approximately 5 mm. FIG. 16A shows that joints1624 and 1628 each have two hinges that pivot around orthogonal axes. Asone hinge pivots in joint 1624, the corresponding hinge pivots an equalamount in the opposite direction in joint 1628. Accordingly, as distalbody segment 1622 moves, the orientation of wrist 1626 and end effector1630 remain essentially unaffected. The hinges are constructed withrolling contact so that cable lengths on each side of the pivot remainbalanced (“virtual pivot points”); details are disclosed in U.S. Pat.No. 6,817,974 (Cooper et al.), which is incorporated by reference. U.S.Pat. No. 6,817,974 further discloses details about theYaw-Pitch-Pitch-Yaw (YPPY; alternately PYYP) arrangement of the hingesin parallel motion mechanism 1632 (wrist 1626 is similarly configured),which provides a constant velocity roll configuration. Consequently,roll of proximal body segment 1620 is smoothly transferred to endeffector 1630. Cables, wires, or bendable hypotubes are routed through acenter channel in body segments 1620,1622, in joints 1624,1628, and inwrist 1626 to operate end effector 1630 (e.g., opening and closing jawsin a gripper as shown). Cables that operate parallel motion mechanism1632 and wrist 1626 are routed through openings near the periphery ofthe joints. FIG. 16B is a perspective view, and FIG. 16C is across-sectional view, of an illustrative embodiment of joints 1624,1628.

As described herein, parallel motion mechanism 1632 includes two joints1624 and 1628. Since the joints 1624,1628 are coupled together, however,they do not operate independently of one another. Therefore, in jointspace the entire parallel motion mechanism 1632 may be considered asingle joint with two degrees of freedom (i.e., pitch and yaw) if“joints” 1624 and 1628 each have two orthogonal hinges (the position ofthe distal end of the mechanism may change in 3D Cartesian space), or asa single joint with one degree of freedom (i.e., pitch or yaw) if“joints” 1624 and 1628 each have a single hinge (the position of thedistal end of the mechanism may change only in 2D Cartesian space). Ifparallel motion mechanism 1632 has two DOFs in joint space, then itfunctions as a constant velocity joint and transmits roll. Mechanism1632's motion is “parallel” because the relative orientations of theproximal and distal ends (frames) of the mechanism remain constant asthe mechanism changes the distal end's (frame's) position.

FIGS. 16D and 16E are schematic views that illustrate aspects ofparallel motion mechanism 1632's design and operation principles. Forclarity, only one set (i.e., PP or YY) of corresponding pivoting hingesis shown. The other set of hinges works the same way. Each hinge has aproximal link disk and a distal link disk. As shown in FIG. 16D, a firstset of cables 1640 a,1640 b are positioned on opposite sides of parallelmotion mechanism 1632 and couple the proximal link disk in hinge 1624 ato the distal link disk in hinge 1628 b. The two cables 1640 a,1640 bare illustrative of various combinations of cables that may be used(e.g., two cables on each side for increased strength; three cablesspaced approximately 120 degrees apart will maintain parallelism in bothplanes; etc.). A second set of cables 1642 a,1642 b are coupled to thedistal link disk of hinge 1624 a and run back through proximal bodysegment 1620 to the transmission mechanism (not shown). Other cablesthat control wrist mechanism 1626 and end effector 1630 are illustratedby a third set of cables 1644 a,1644 b.

As shown in FIG. 16E, when the transmission mechanism applies a tensileforce on cable 1642 a (cable 1642 b is allowed to pay out), hinge 1624 apivots. The cable 1640 a,1640 b coupling between the proximal link diskof hinge 1624 a and the distal link disk of hinge 1628 a causes hinge1628 a to pivot an equal amount in the opposite direction. Consequently,wrist 1626 and end effector 1630 are laterally displaced away fromlongitudinal axis 1619 of proximal body segment 1620. The lengths ofcables 1644 a,1644 b are unaffected by the movement because of the hingedesign, and so wrist 1626 and end effector 1630 orientation are alsounaffected by the movement. If proximal instrument body segment 1620were to remain stationary, then end effector 1630 translates slightly ina direction aligned with longitudinal axis 1619 (surged) in thepatient's reference frame. Therefore, the control system, describedbelow, compensates for this small movement by moving proximate bodysegment 1620 by an amount necessary to keep end effector 1630 at aconstant insertion depth in the patient's reference frame.

In some instances when transmitting roll to the end effector is notrequired (e.g., for suction or irrigation tools, for an imaging system),each joint in the parallel movement mechanism may have only a singlepivoting hinge. Further, skilled artisans will understand that ifkeeping end effector orientation is not required, then the parallelmotion mechanism may be omitted. For instance, a proximal instrumentbody segment may be coupled to a distal instrument body segment at ajoint with a single pivoting axis so that the proximal body segment mustbe rolled to move an end effector at the distal end of the distal bodysegment from side to side. Or, two or more elongated distal bodysegments may be used. If roll is not required, then the cross section ofthe body segments does not have to be round. In some aspects, the wristmechanism may be eliminated.

FIG. 16F is a diagrammatic end view of a link disk, and it illustratesaspects of cable routing in a parallel motion mechanism. As shown inFIG. 16F, twelve cable routing holes are placed near the outsideperimeter of link disk 1650. The cable routing holes are spaced 22.5degrees apart from one another between the 3, 6, 9, and 12 O'clockpositions on link disk 1650. Holes are not placed at the 3, 6, 9, and 12O'clock positions because of the hinge components (not shown) on theobverse and reverse sides of link disk 1650. Starting at the 12 O'clockposition, the holes are labeled 1652 a-1652 l. Four sets of three cableseach are dedicated to four functions. A first set of cables maintainsthe parallel function in the parallel motion mechanism and are routedthrough holes 1652 a, 1652 e, and 1652 i. A second set of cables areused to move a distal part of a wrist mechanism (e.g., wrist mechanism1626) and are routed through holes 1652 b, 1652 f, and 1652 j. A thirdset of cables are used to move the parallel motion mechanism and arerouted through holes 1652 c, 1652 g, and 1652 k. A fourth set of cablesare used to move a proximal part of the wrist mechanism and are routedthrough holes 1652 d, 1652 h, and 1652 l. Cables and other componentsassociated with an end effector are routed through central hole 1654 inlink disk 1650.

FIG. 16G is another diagrammatic end view of a link disk, and itillustrates further aspects of cable routing in a parallel motionmechanism. As shown in FIG. 16G, a first set of 12 cable routing holesare placed around the outside perimeter of link disk 1660 in a mannersimilar to those shown in FIG. 16F. In addition, a second set of 12cable routing holes are placed around a concentric circle inside thefirst set of holes. Starting at the 12 O'clock position, the outer ringof cable routing holes are labeled 1662 a-1662 l, and the inner ring ofholes are labeled 1664 a-1664 l. Cables associated with the parallelmotion mechanism are routed through the outer ring of holes 1662, andcables associated with the wrist mechanism are routed through the innerring of holes 1664. A first set of three cable pairs maintains theparallel function in the parallel motion mechanism and are routedthrough adjacent holes 1662 a and 1662 l, 1662 d and 1662 e, and 1662 hand 1662 i. A second set of three cable pairs are used to move theparallel motion mechanism and are routed through adjacent holes 1662 band 1662 c, 1662 f and 1662 g, and 1662 j and 1662 k. A third set ofthree cable pairs is used to move a proximal part of the wrist mechanismand are routed through adjacent holes 1664 a and 1664 l, 1664 d and 1664e, and 1664 h and 1664 i. A fourth set of three cable pairs are used tomove a distal part of the wrist mechanism and are routed throughadjacent holes 1664 b and 1664 c, 1664 f and 1664 g, and 1664 j and 1664k. Cables and other components associated with an end effector arerouted through central hole 1666 in link disk 1660.

The use of cable pairs as illustrated in FIG. 16G increases actuationstiffness above the stiffness of using a single cable. The increasedstiffness allows the instrument components to be more accuratelypositioned during movement (e.g., the increased stiffness helps toreduce motion hysteresis). In one example, such cable pairs are used foran instrument with a parallel motion mechanism that is approximately 7mm in diameter. Instruments with smaller diameters (e.g., approximately5 mm in diameter), however, may not have sufficient internal space toaccommodate cable pairs. In these situations, single cables routed inaccordance with FIG. 16F may be coupled to a cable on the opposite sideof the parallel motion mechanism. Aspects of such coupling areillustrated in FIGS. 16H-16J.

FIG. 16H is a diagrammatic perspective view of a stiffening bracket 1670that couples cables routed on opposite sides of a parallel motionmechanism's body segment 1622. Bracket 1670 has a cross piece 1672 andtwo parallel support members 1674 attached (e.g., welded) on oppositesides of cross piece 1672. A hypotube 1676 is attached (e.g., welded) toeach support member so that the hypotubes are parallel to each other.The hypotubes 1676 are spaced apart a distance slightly less than thefree space distance between the two cables to be coupled. The cable 1678that maintains the parallel motion mechanism's parallel function isthreaded through its associated hypotube 1676 as the cable extendsbetween its two anchor points in the parallel motion mechanism. Thehypotube 1676 is crimped to keep cable 1678 in place. The end of cable1680 that is used to move the parallel motion mechanism is threaded intoits associated hypotube 1676, which is crimped to keep cable 1680 inplace. Consequently, the distal end of cable 1680 is anchored to amiddle position (not necessarily halfway) of cable 1678. Referring toFIG. 16F, cables running through holes 1652 a and 1652 g are coupledtogether, cables running through holes 1652 c and 1652 i are coupledtogether, and cables running through holes 1652 e and 1652 k are coupledtogether. FIG. 16I illustrates an aspect of how multiple brackets 1670may be positioned within the body of a parallel motion mechanism. Thatis, each cable that is associated with moving the parallel motionmechanism is coupled to an opposite side cable associated withmaintaining the parallel function of the parallel motion mechanism.

Due to the way the hinges are constructed, described above, the cablesthat maintain the parallel function move within the body of the parallelmotion mechanism, even though they are anchored at either end of theparallel motion mechanism. Therefore, for a given motion of the parallelmotion mechanism, the cable coupling requires that the cables 1680,which move the parallel motion mechanism, move twice as far as theywould if they were anchored to the parallel motion mechanism's bodysegment as illustrated in, e.g., FIGS. 16D-16E. The effect of thiscoupling increases joint stiffness approximately four times more thannon-coupled cables because the cable moves twice as far, and because theload on the cable is half as great for a given joint torque.

FIG. 16J is a diagrammatic end view of a stiffening bracket 1670. Asshown in FIG. 16J, cross piece 1672 is hollow so that cables and othercomponents associated with an end effector may be routed through thecross piece. In one aspect, cross piece 1672 is made using electricaldischarge machining. Referring again to FIG. 16, the proximal bodyportion, parallel motion mechanism, wrists and end effector are alignedalong longitudinal axis 1619 to allow the instrument to be inserted andwithdrawn through guide tube 1606. Accordingly, two or moreindependently operating, exchangeable instruments, each with parallelmotion mechanisms, can be simultaneously inserted via guide tube 1606 toallow a surgeon to enter a patient via a single entry port and workwithin a large volume deep within a patient. Each independentinstrument's end effector has a full 6 DOF in Cartesian space(instrument insertion and the parallel motion mechanism provide thetranslation DOFs, and instrument body roll and the wrist mechanismprovide the orientation DOFs). Further, the instruments 1602 a,1602 bmay be partially withdrawn so that, e.g., only the wrist and endeffectors extend from the guide tube 1606's distal end 1610. In thisconfiguration, the one or more wrists and end effectors can performlimited surgical work.

FIG. 17 is a schematic view that illustrates aspects of a thirteenthminimally invasive surgical instrument assembly 1700. Surgicalinstrument assembly 1700 is similar to instrument assembly 1600 (FIGS.16-16J) in that surgical instruments 1702 a,1702 b function similarly toinstruments 1602 a,1602 b as described above, but instead of a fixedendoscopic imaging system at the end of the guide tube, assembly 1700has an independently operating endoscopic imaging system 1704.

In one aspect, imaging system 1704 is mechanically similar to surgicalinstruments 1602 as described above. Summarizing these aspects as shownin FIG. 17, optical system 1704 includes a substantially rigid elongatetubular proximal body segment 1706 that extends through guide tube 1708,and at proximal body segment 1706's distal end there is coupled a 1 or 2DOF parallel motion mechanism 1712 that is similar to parallel motionmechanism 1622 (FIGS. 16-16J). Parallel motion mechanism 1712 includes afirst joint 1714, an intermediate distal body segment 1716, and a secondjoint 1718. As shown in FIG. 17, in some aspects a wrist mechanism orother active joint (e.g., one DOF to allow changing pitch angle; twoDOFs to allow changing pitch and yaw angles) 1720 couples an imagecapture component 1722 to second joint 1718. Alternatively, in anotheraspect joint 1714 is an independently controllable one or two DOF joint(pitch/yaw), joint 1718 is another independently controllable one or twoDOF joint (e.g., pitch/yaw), and image capture component 1722 is coupleddirectly at the distal end of the joint 1718 mechanism. An example of asuitable stereoscopic image capture component is shown in U.S. patentapplication Ser. No. 11/614,661, incorporated by reference above. Insome aspects imaging system 1704 moves longitudinally (surges) insideguide tube 1708. Control of imaging system 1704 is further described inconcurrently filed U.S. patent application Ser. No. 11/762,236 (Diolaitiet al.) entitled “Control System Configured to Compensate for Non-IdealActuator-to-Joint Linkage Characteristics in a Medical Robotic System”,which is incorporated by reference. In some aspects, roll may beundesirable because of a need to preserve a particular field of vieworientation. Having heave, sway, surge, yaw, and pitch DOFs allows theimage capture component to be moved to various positions whilepreserving a particular camera reference for assembly 1700 and viewingalignment for the surgeon.

FIG. 17A is, for illustrative purposes only, a side view schematic toFIG. 17's plan view schematic. FIG. 17A shows that parallel motionmechanism 1712 moves image capture component 1722 away from surgicalinstrument assembly 1700's longitudinal centerline. This displacementprovides an improved view of surgical site 1724 because some or all ofthe instrument body distal segment ends are not present in the imageoutput to the surgeon as would occur in, e.g., instrument assembly 1600(FIG. 16). The pitch of parallel motion mechanism 1712 and of imagecapture component 1722 is controllable, as illustrated by the arrows.

FIG. 17B is a diagrammatic perspective view that illustrates anembodiment of surgical instrument assembly 1700. As shown, twoindependently teleoperated surgical instruments 1740 a,1740 b (eachinstrument is associated with a separate master—e.g. one left handmaster for the left instrument and one right hand master for the rightinstrument) run through and emerge at the distal end of a rigid guidetube 1742. Each instrument 1740 a,1740 b is a 6 DOF instrument, asdescribed above, and includes a parallel motion mechanism 1744 a,1744 b,as described above, with wrists 1746 a,1746 b and end effectors 1748a,1748 b attached. In addition, an independently teleoperated endoscopicimaging system 1750 runs through and emerges at the distal end of guidetube 1742. In some aspects imaging system 1750 also includes a parallelmotion mechanism 1752, a pitch-only wrist mechanism 1754 at the distalend of the parallel motion mechanism 1752 (the mechanism may have eitherone or two DOFs in joint space), and a stereoscopic endoscopic imagecapture component 1756 coupled to wrist mechanism 1754. In otheraspects, wrist mechanism 1754 may include a yaw DOF. In yet anotheraspect, the proximal and distal joints in imaging system 1750 areindependently controlled. In an illustrative use, parallel motionmechanism 1752 heaves and sways image capture component 1756 up and tothe side, and wrist mechanism 1754 orients image capture component 1756to place the center of the field of view between the instrument tips ifthe instruments are working to the side of the guide tube's extendedcenterline. In another illustrative use, the distal body segment ofimaging system is independently pitched up (in some aspects alsoindependently yawed), and image capture component 1756 is independentlypitched down (in some aspects also independently yawed). As discussedabove and below, imaging system 1750 may be moved to various places toretract tissue.

Also shown is an auxiliary channel 1760, through which, e.g.,irrigation, suction, or other surgical items may be introduced orwithdrawn. In some aspects, one or more small, steerable devices (e.g.,illustrated by instrument 902 in FIG. 9) may be inserted via auxiliarychannel 1760 to spray a cleaning fluid (e.g., pressurized water, gas)and/or a drying agent (e.g., pressurized air or insufflation gas) on theimaging system's windows to clean them. In another aspect, such acleaning wand may be a passive device that attaches to the camera beforeinsertion. In yet another aspect, the end of the wand is automaticallyhooked to the image capture component as the image capture componentemerges from the guide tube's distal end. A spring gently pulls on thecleaning wand so that it tends to retract into the guide tube as theimaging system is withdrawn from the guide tube.

FIG. 17A further illustrates that as image capture component 1722 ismoved away from assembly 1700's centerline it may press against and movean overlying tissue structure surface 1726, thereby retracting thetissue structure from the surgical site as shown. The use of imagingsystem 1704 to retract tissue is illustrative of using other surgicalinstruments, or a device specifically designed for the task, to retracttissue. Such “tent-pole” type retraction may be performed by any of thevarious movable components described herein, such as the distal end exitor side exit flexible devices and the parallel motion mechanisms on therigid body component devices, as well as other devices discussed below(e.g., with reference to FIG. 31).

In some aspects, one or more surgical instruments may exit from a guidetube generally aligned with the guide tube's longitudinal axis but notat the guide tube's distal end. FIG. 18 is a schematic view thatillustrates aspects of a fourteenth minimally invasive surgicalinstrument assembly 1800. As shown in FIG. 18, a first surgicalinstrument 1802 runs coaxially through primary guide tube 1804, and asecond surgical instrument 1806 runs coaxially through primary guidetube 1808. Instrument and primary guide tube combinations 1802,1804 and1806,1808 are illustrative of the various flexible and rigid instrumentsand instrument/guide tube combinations described above. Instrument/guidetube combination 1802,1804 extends through and exits at secondary guidetube 1810's extreme distal end 1812. Instrument/guide tube combination1806,1808 extends through secondary guide tube 1810 and exits at anintermediate position 1814 that is proximally spaced from extreme distalend 1812. In contrast to the side exits that direct instruments awayfrom the guide tube's longitudinal axis as shown in, e.g., assemblies1300 (FIG. 13) and 1400 (FIG. 14), instrument/guide tube combination1806,1808 exits generally aligned with secondary guide tube 1810'slongitudinal axis 1816. The distal and intermediate position guide tubeface angles may be other than perpendicular to axis 1816.

FIG. 18 also shows that endoscopic imaging system 1818 is positioned onsecondary guide tube 1810 between extreme distal end 1812 andintermediate position 1814. Imaging system 1818's field of view isdirected generally perpendicular to longitudinal axis 1816. Duringsurgery (e.g., within a long, narrow space), the surgical site islocated within imaging system 1818's field of view and instrument/guidetube combinations 1802,1804 and 1806,1808 (working somewhat retrogradefrom its distal end 1812 exit) are moved to work at the surgical site.Imaging system 1818 is, in some aspects, an electronic stereoscopicimage capture system. In some aspects, a second imaging system 1820(e.g., a monoscopic system with lower resolution than imaging system1818) is located to have a field of view generally aligned with axis1816 to assist instrument assembly 1800 insertion. It can be seen thatthe architecture illustrated in FIG. 18 allows the guide tube's crosssection to be relatively small—enough to accommodate the instrumentsand/or guide tubes that run through it (see e.g., FIG. 11B andassociated description)—but the imaging system dimensions (e.g., theinterpupillary distance in a stereoscopic system) can be larger than ifpositioned at the guide tube's distal end face.

FIG. 18A is a schematic view that illustrates further aspects of animaging system at the distal end of an illustrative instrument assembly1801. As shown in FIG. 18A, one or more instruments and/orinstrument/guide tube combinations exit from guide tube 1811'sintermediate position 1814 as described above. Guide tube 1811's distalend segment 1822 is pivotally mounted so that it can be pitched inrelation to guide tube 1811's main segment as shown by alternateposition lines 1823, although not necessarily pivoting near theintermediate position as depicted. Alternate position 1823 isillustrative of various movements and mechanisms. For example, in oneaspect a parallel motion mechanism as described above is used todisplace imaging system 1818. In another example, alternate position1823 represents positioning and orienting imaging system 1818 with twoindependently controllable 1 or 2 DOF joints. Other combinations ofjoints and links may be used. Accordingly, imaging system 1818's fieldof view direction can be altered, space permitting in the surgicalsite's vicinity. Distal end 1822 may be positioned above the exit portsas shown in FIG. 18A, or it may be positioned between the exit ports toprovide a smaller instrument assembly cross section as illustrated byFIG. 18F.

FIG. 18B is another schematic view which shows that an imaging system1824 may pivot in distal end segment 1822, as shown by the alternateposition lines and arrow. Pivoting imaging system 1824 may be at theextreme distal end of the guide tube, or it may be positioned somewhatproximally from the extreme distal end (in which case in some aspectsthe second imaging system 1820 can be positioned at the distal end toprovide viewing along the instrument assembly's longitudinal axis whileimaging system 1824 is viewing to the side).

FIG. 18C is a diagrammatic perspective view of an embodiment of aminimally invasive surgical instrument assembly that incorporatesaspects of instrument assemblies 1800 and 1801. As shown in FIG. 18C,two surgical instruments 1830 a,1830 b, each with rigid, movable distallinks, extend from intermediate position 1832 on guide tube 1834. Eachinstrument 1830 a,1830 b includes an upper arm link 1836, a lower armlink 1838, and an end effector 1840 (illustrative grippers are shown). Ashoulder joint 1842 couples upper arm link 1836 to the instrument body(not shown) that extends back through guide tube 1834. An elbow joint1844 couples upper arm link 1836 to lower arm link 1838, and a wristjoint 1846 couples lower arm link 1838 to the end effector 1840. In someaspects, parallel motion mechanisms as described above with reference toFIGS. 16A-16J may be used, and in other aspects the shoulder and elbowjoints may be independently controlled, as are the wrist joints 1846. Insome aspects only a single arm link is used; in others more than two armlinks are used. In some aspects, one or both shoulder joints 1842 arefixed to guide tube 1834 so that there is no associated instrument body.

FIG. 18C further shows that a stereoscopic imaging system 1850 ismounted near the extreme distal end 1852 of guide tube 1834. As shown,imaging system 1850 includes right and left image capture elements 1854a,1854 b, which may be positioned behind protective imaging ports, andillumination output ports (LEDs, optical fiber ends, and/or associatedprisms that direct illumination light as desired) 1856. As describedabove, imaging system 1850's field of view is generally perpendicular toguide tube 1834's longitudinal axis so that a surgeon clearly sees endeffectors 1840 working at a surgical site to the side of guide tube1834's distal end. And, the axis between the imaging apertures ispreferably generally parallel to a line between the surgical instrumenttips, an alignment that presents to the surgeon an orientation in whichthe instrument tips map into natural and comfortable hand positions atthe master console. In some aspects, as illustrated in FIG. 18A, guidetube 1834's distal end pivots at a joint 1858 so that imaging system1850's field of view direction can be changed, as described above. Joint1858 may be positioned at various locations on guide tube 1834. In oneaspect, guide tube 1834 is approximately 12 mm outer diameter, theinstruments are approximately 5 mm outer diameter, and imaging system1850's lenses are about 3 mm across with an interpupillary distance ofabout 5 mm. FIG. 18D is a diagrammatic perspective view that illustrateshow the distal end pitches up and down so that imaging system 1850 canlook forwards (toward the distal direction; anterograde viewing) orbackwards (toward the proximal direction; retrograde viewing).

As mentioned elsewhere in this description, although many aspects andembodiments are shown and described as having instruments and/or guidetubes that extend through other guide tubes, in other aspectsinstruments and/or guide tubes may be fixed at the end of, or atintermediate positions on, an instrument assembly structure so as to beintegral with that structure. In some aspects, the fixed instrumentsand/or guide tubes may, however, be replaceable in vitro if thestructure is removed from a patient. For example, a surgeon may removethe instrument assembly from the patient, replace one or moreinstruments that are attached (e.g., using known mechanisms) at the endor at an intermediate position with one or more other instruments, andthen reinsert the instrument assembly.

FIG. 18E is a diagrammatic perspective view of an embodiment of aminimally invasive surgical instrument in which a movable surgicalinstrument 1860 (e.g., a U-Turn instrument as described below, aflexible arm, a multilink arm, and the like) is fixed at the extremedistal end 1861 of a guide tube 1862. Thus, the combination of guidetube 1862 and instrument 1860 functions in a manner similar to segments15 a and 15 b of instrument 15 as shown and described in FIG. 2B. Inaddition, a second surgical instrument 1864 is either fixed at anintermediate position 1866 on guide tube 1862 or is removable asdescribed above. And, as described above, an imaging system 1868 with afield of view direction generally perpendicular to guide tube 1862'slongitudinal axis is positioned near guide tube 1862's distal end.

During insertion, in one aspect instrument 1860 is straightened to begenerally aligned with the longitudinal axis, and instrument 1864 iseither similarly aligned with the longitudinal axis (if fixed; ifremovably attached) or is at least partially withdrawn into the guidetube. Alternatively, in another aspect instrument 1860 may beretroflexively folded back against guide tube 1862. An optional secondimaging system 1870 positioned at distal end 1861 may be used to assistinsertion as described above.

FIG. 18F is an illustrative diagrammatic plan view of another aspect ofa surgical instrument assembly with a movable imaging system at thedistal tip of a guide tube. As depicted in FIG. 18F, an endoscopic imagecapture component 1880 is at the distal end of parallel motion mechanism1884, which is coupled at the distal end of guide tube 1882. As shown,parallel motion mechanism 1884 has a single DOF in joint space so thatit moves image capture component 1880 out of the page, towards theperson looking at the figure. In some aspects, parallel motion mechanismmay be thinner (between the two instruments) than shown in the figuresince it has only one DOF as shown. In other aspects, parallel motionmechanism 1884 may have two DOFs as described above. Alternatively, twoindependently controllable joints may be used, with each joint generallyplaced where the hinges are shown in parallel motion mechanism 1884. Inone aspect guide tube 1882 has an oblong cross section, as illustratedby FIG. 11B.

Additional DOFs may be used to orient image capture component 1880. Forexample, FIG. 18G illustrates that an independent yaw joint 1886 may beplaced between parallel motion mechanism 1884 and image capturecomponent 1880. Joint 1886 is illustrative of various single andmultiple DOF joints that may be used (e.g., pitch or pitch/yaw). Asillustrated below in FIG. 19J, in one aspect a flexible arm may be usedinstead of parallel motion mechanism 1884. Optics in image capturecomponent 1880 may provide a down looking angle (e.g., 30 degrees).

FIG. 18F further shows that in one aspect parallel motion mechanism 1884is long enough to allow the parallel motion mechanisms, wristmechanisms, and end effectors of independently controllable instruments1888 a and 1888 b to extend though intermediate position exit ports 1890a and 1890 b in guide tube 1882 and move while image capture component1880 is still aligned with the center of guide tube 1882. When parallelmotion mechanism 1884 moves image capture component 1880 away from beingaligned with guide tube 1882, instruments 1888 a and 1888 b can extendunderneath image capture component 1880 to reach a surgical site.

FIG. 19 is a diagrammatic perspective view that illustrates aspects of afifteenth minimally invasive surgical instrument assembly, showing anillustrative distal segment 1900 of the assembly. This assembly 1900,like some of the variations of assembly 1800 (FIGS. 18-18G), isprimarily intended for surgical work to be performed generally to theside of the assembly rather than in front of its distal end. In theembodiment shown in FIG. 19, a first surgical instrument 1902, a secondsurgical instrument 1904, and an imaging system 1906 extend through aguide tube 1908. Various combinations of instruments and imaging systemsmay be used, either removable or fixed as described above. Surgicalinstrument 1902 generally works like the various instruments describedabove, its distal segment 1902 a being rigid or flexible as described.And, instrument 1902 is illustrative of aspects in which is used aprimary guide tube and instrument combination as described above. Guidetube 1908 may be rigid or flexible as described above. The surgicalinstrument bodies are, e.g., about 7 mm in diameter.

The image capture system in imaging system 1906 has a field of view thatis generally perpendicular to instrument assembly 1900's longitudinalaxis so that the surgeon can work at a site located to the side of theassembly. Imaging system 1906 may translate longitudinally (surge)within a channel defined in guide tube 1908, may be fixed to the distalend of guide tube 1908, or may be an integral part of guide tube 1908 asillustrated by aspects of assembly 1800 (FIGS. 18-18G). In some aspectswith a round instrument body, imaging system 1906 may roll within thechannel. The round instrument body must be large enough to accommodate,e.g., sensor data wiring (unless a wireless link is used) and an opticalfiber illumination bundle. In other aspects the distal end 1912 alonemay roll about imaging system 1906's longitudinal axis, as shown by thearrows, so as to place the surgical site within the field of view. Ifthe distal end 1912 alone rolls, then an interface allows the sensordata wiring (unless a wireless link is used) and, e.g., power wires oroptical fibers for illumination to bend to accommodate the roll.

Surgical instrument 1904 is designed to work primarily in retrograde. Asshown in FIG. 19, the distal segment 1904 a of instrument 1904 is joinedto a body segment 1904 b by a U-Turn mechanism 1904 c. Components (suchas, e.g., levers, pulleys, gears, gimbals, cables, cable guide tubes,and the like) inside U-turn assembly 1904 c transmit mechanical forces(e.g., from cable or cable/hypotube combinations) around the U-turn (notnecessarily 180 degrees as shown; other turn angles may be used) to movedistal segment 1904 a and an optional wrist mechanism, and to operate anend effector (not shown). U-Turn mechanism 1904 c is distinguished fromflexible mechanical structures because, e.g., it transmits mechanicalforces through a radius of curvature that is significantly less than theminimum radius of curvature of equivalently sized flexible mechanicalstructures. Further, since the U-Turn mechanism does not itself move,the distance between a point where an actuating force enters the U-Turnmechanism and the point where the actuating force exits the U-Turnmechanism is unchangeable. For aspects in which a joint is placed inbody segment 1904 b so that it is divided into proximal and distalsegments, and if instrument body roll is not transmitted through thejoint, then the distal tip 1904 d may be configured to rotate around thedistal segment's longitudinal axis.

FIG. 19A is another diagrammatic perspective view of the embodimentdepicted in FIG. 19, and it illustrates that during surgical work thedistal ends of instruments 1902 and 1904 are generally within imagingsystem 1906's field of view to the side of assembly 1900.

FIGS. 19 and 19A further show that in some aspects the surgicalinstrument distal ends are coupled to the main bodies at a single pivotpoint 1914. Movement in more than one plane is facilitated by, e.g., aball and socket type joint as illustrated above in FIG. 18C (1842) andbelow in FIGS. 19B and 19C. In other aspects, joints such as those shownin FIGS. 16A-C are used. End effectors (not shown) may be coupleddirectly or via wrist mechanisms at the extreme distal ends 1916.

FIG. 19B is a plan view of a surgical instrument assembly embodimentthat incorporates a U-turn surgical instrument 1920. Distal instrumentforearm segment 1922 is coupled to instrument main body segment 1924 viaU-Turn mechanism 1926 and an illustrative controllable ball joint 1928.Wrist 1930 (ball and annular segment flexible mechanism is shown forillustration; other wrist mechanisms may be used as described above)couples end effector 1932 to the distal end of forearm segment 1922.Cables (not shown) that move forearm 1922, wrist 1930, and end effector1932 are routed through individual cable guides in U-Turn mechanism1926, as described in more detail below. The alternate position lines1934 illustrate that in some instances wrist 1930 can bend at least 135degrees in three dimensions to enable end effector 1932 to be orientedin various useful ways. An embodiment of such a wrist may incorporate,e.g., three 2-DOF joints of two hinges each, as described above withreference to FIGS. 16A-C. Each 2-DOF joint allows about 45 degrees ofpitch and yaw from being aligned with forearm link 1922's longitudinalaxis. In some aspects, rather than using the indexed joints as shown, aparallel motion mechanism and wrist combination as described above maybe used. The surgical instrument assembly shown in FIG. 19C alsoincorporates a second surgical instrument 1936 that operates similarlyto instrument 1920, except that it does not incorporate the U-Turnmechanism.

FIG. 19C is another plan view of the surgical instrument assemblyembodiment shown in FIG. 19B, with surgical instrument 1920 extendedfarther out of guide tube 1938. In FIG. 19B, the end effectors areworking close to and pointing generally at imaging system 1940. In FIG.19C, the end effectors are still working close to imaging system 1940,but they are now pointing generally perpendicular to imaging system1940's viewing angle. Thus FIG. 19C illustrates that instrument 1920'sextension distance from guide tube 1938 may depend on the end effectorangle commanded by a master input control. It can also be seen that insome aspects if a command is given to change the end effector'sorientation while maintaining its position, then the instrument body andforearm link must be moved to a new pose.

FIG. 19D is an exploded perspective view that illustrates aspects ofrouting cables (the term “cable” is illustrative of various filars(herein, the term “filars” should be broadly construed and includes,e.g., single- and multi-strand threads or even very fine hypotubes) thatmay be used) that control distal instrument components through a U-Turnmechanism. As shown in FIG. 19D, actuator cables 1950 for, e.g., forearmlink 1922, wrist 1930, and end effector 1932 run through instrument mainbody segment 1924 and are routed through individual cable guide tubes1952, which route cables 1950 around the U-Turn. The cable guide tubesare, e.g., stainless steel hypotubes. Brace 1954 clamps and thereforestabilizes both ends of the cable guide tubes 1952. Alternatively, or inaddition, the cable guide tubes may be soldered or brazed. An outercover may cover and protect the cable guide tubes and also any tissueagainst which the U-Turn instrument may press as it extends from itsguide tube. In the embodiment shown, each individual cable guide tube isapproximately the same length and has approximately the same bend radius(there are some small differences, as shown in the Figures). Theapproximately equal length and bend radius tubes make each cable'scompliance, a function of diameter and length, approximately the same.Friction depends on the load and total bend angle of each cable.

In this illustrative embodiment, 18 cable guide tubes are shown. Tocontrol distal DOFs, the theoretical minimum number of tension cables isDOFs+1. More cables can be used for simplicity, to increase strength orstiffness, or to constrain joint behavior. In an illustrative 5 mm wristmechanism as shown above, for example, two of the hinges are slavedthrough cables to two other hinges. In this example, 18 cables would beused to control 4 distal DOFs plus end effector grip. In someembodiments there is no roll control for the wrist mechanism. Endeffector roll is provided by rolling the instrument body shaft insidethe guide tube. With coordinated movement of the other joints, rollingthe instrument body shaft will roll the end effector around its endpoint.

FIG. 19E is a perspective view of an illustrative embodiment of thecable guide tubes 1952. A total of 18 cable guide tubes are shown. Thecable guide tubes are arranged so as to form a central channel 1955,through which may be routed control cables for an end effector, surgicalimplements for suction, irrigation, or electrocautery, and the like. Anoptional sleeve (not shown) may be inserted within channel 1955 toreduce friction. Other numbers of guide tubes (e.g., 9) may be used.

FIG. 19F is an end elevation view that shows the arrangement of guidetubes 1952 around the central channel 1955.

FIG. 19G is a perspective view of an illustrative embodiment of analternate way of routing cables around the U-Turn. Instead of using themultiple cable guide tubes 1952 and brace 1954, they are constructed asa single part 1956. Metal casting or rapid metal prototyping is used tomake the part, which includes individual channels 1957 through which thecables are routed, and a central channel 1958 through which othercomponents may be routed as discussed above.

FIG. 19H is a perspective view that illustrates aspects of a surgicalinstrument with a U-Turn mechanism passing through and exiting from aguide tube. A single channel 1960 in guide tube 1962 is shaped toaccommodate both the instrument's main body segment 1924 and theretrograde segment 1964 (only the control cables for the retrogradesegment are shown; see e.g., FIG. 19B), which is folded back towards themain body segment as the instrument moves within the channel. Thechannel is pinched in the middle, so that when the U-Turn mechanism andretrograde segment exit the guide tube, the portion of the channelthrough which the main body segment passes still securely holds the mainbody segment. The single piece U-Turn part 1956 is also pinched as shownso that they slide within channel 1960. Once retrograde segment 1964 hasexited guide tube 1962, a second instrument may be inserted through theportion of channel 1960 through which retrograde segment 1964 passed.Various other channel shapes that allow multiple instruments to beinserted through the guide tube are described in more detail below.

FIG. 19I is a perspective view that illustrates that once the U-Turninstrument exits the guide tube it may be rolled within the channel andthen the forearm link can be moved so that the end effector ispositioned within the imaging system's field of view. In one aspect,keeping the end effector in position and rolling the instrument bodywithin the guide tube rolls the end effector, as shown by the rotationalarrows, because of the nature of the joints.

FIG. 19J is a perspective view that illustrates aspects of a surgicalinstrument assembly embodiment that uses more than one U-Turn retrogradesurgical instrument. Using two U-Turn instruments allows the endeffectors to work back closely to the guide tube. In order to provideimage capture for the surgeon, an illustrative independent imagingsystem 1970 is shown with an image capture component 1972 mounted at theend of an illustrative flexible mechanism 1979. A U-Turn mechanism or aseries of rigid links may be used instead of a flexible mechanism.Retroflexing the imaging system allows image capture component 1972'sfield of view to encompass the two U-Turn instrument end effectors.Alternatively, an imaging system 1976 may be positioned at the side ofthe guide tube if the end effectors are to work generally to the side ofthe instrument assembly.

FIG. 19K is a plan view that illustrates another aspect of the U-turnmechanism 1990, which uses small levers, for example, to transmit forcesfrom the main instrument body to the distal forearm link, wristmechanism, and end effector. Various cables, wires, rods, hypotubes, andthe like, and combinations of these components, may be used in the mainbody and forearm and are coupled to the force transmission components.

Depending on the location of the surgical work site in relation to theinstrument assembly and instruments to be used, illumination for theimaging system may be positioned at various places in side- andretroflexive-working systems. In addition to, or instead of, having oneor more illumination output ports near the image capture component asdescribed above, one or more illumination LEDs may be placed on the bodyof the retroflexive tool. Referring to FIG. 19C, for example, one ormore LEDs may be placed at an illustrative position 1942, alonginstrument main body segment 1924. Or, LEDs may be placed along theforearm segment at, e.g., 1938 as shown in FIG. 19B. Likewise, LEDs maybe placed at the inner curve of a retroflexing flexible mechanism, suchas at positions 1978 shown in FIG. 19J. An advantage of placingadditional illumination some distance away from the imaging apertures isthat the additional illumination may provide shadows, which providesbetter depth cues. Illumination near or surrounding the imagingapertures, however, prevents the shadows from becoming so deep thatdetails are not visible in the shadowed areas. Accordingly, in someaspects illumination both near to and far from the imaging apertures isused.

One or more channels, illustrated by dashed lines 1944 (FIG. 19C) or1980 (FIG. 19J), in the structure on which the LEDs are mounted maycarry cooling fluid (e.g., water) past the LEDs. The LED die (ormultiple LED die) can be mounted on the obverse side of a thermallyconductive substrate (e.g., an aluminum plate, a plated ceramic), whichis bonded to the cooling channel so that the reverse side of thesubstrate is exposed to the cooling flow. Techniques for bonding LEDs tosubstrates are well known and can be adapted for use with liquidcooling. The cooling fluid may circulate in a closed system, or it mayempty either inside or outside the patient. For an open cooling systemthat empties into the patient, a sterile, biocompatible fluid (e.g.,sterile isotonic saline) is used. Suction may be used to remove thecooling fluid from the patient. In addition, the cooling fluiddischarged into the patient may be used to perform other functions. Forexample, the discharged cooling fluid may be directed across the imaginglenses. The fluid may clean the lenses or prevent body fluids, smoke, orsurgical debris from sticking to the lenses.

The amount of cooling fluid to keep an LED within an acceptabletemperature range is fairly small. For example, an LED that dissipatesabout 4 Watts of electrical power as heat can be cooled with a flow ofabout 0.1 cc/sec of water through 0.020-inch OD plastic tubing (e.g., 12feet total length; 6 feet supply and 6 feet return), and the water willexperience only about a 10-degree Celsius temperature rise.

The use of LEDs as described above is an example of alternativeillumination placement on the instruments. In some aspects, fiber lightguides may be used, in which case cooling considerations do not apply.

As discussed above, in some aspects the cross-sectional area of a guidetube must accommodate instruments which themselves have distal portionswith a relatively large cross-sectional area. In order to minimize theguide tube's cross-sectional area, in one aspect more than oneinstrument is inserted through a single specially shaped channel.

FIG. 20A is an end elevation view of the distal end face of illustrativeguide tube 2002. Guide tube 2002's lateral cross section is similarlyconfigured (i.e., the channels depicted extend through the entire guidetube). As shown in FIG. 20A, guide tube 2002 has three channels (more orfewer channels may be used). Channel 2004 accommodates an endoluminalimaging system and may have various cross-sectional shapes (e.g., round,oval, rounded polygon, etc.). The shape illustrated in FIG. 20A is acircle overlaid and centered on a rounded rectangle. The circular bore2004 a of channel 2004 accommodates the imaging system's body(illustrated by dashed lines), and the slots 2004 b (the ends of therounded rectangle) on either side of the circular bore 2004 a allow theimage capture element which is wider than the cylindrical body segment,to pass through channel 2004. Since the circular bore 2004 a has aslightly larger diameter than slots 2004 b (the channel 2004 crosssection is an oblong, biconvex shape), the imaging system's body segmentis held in place within channel 2004 after the image capture elementexits guide tube 2002's distal end.

Channel 2006, depicted as a single, circular bore, is an optionalauxiliary channel and may be used for irrigation, suction, small (e.g.,3 mm diameter) instruments, etc.

Channel 2008 is uniquely shaped to simultaneously accommodate twosurgical instruments in which one has a distal end segment larger thanits body segment, such as instruments 1902 and 1904 (FIG. 19). As shownin FIG. 20A, channel 2008's cross-sectional shape is generally oblongwith a pinched center across the major axis (the cross section is anoblong, biconcave shape). Channel 2008 includes two cylindrical bores2008 a,2008 b through which cylindrical instrument bodies are inserted.The bores 2008 a,2008 b are interconnected by a slot 2008 c. As aninstrument body (illustrated by the circular dashed line 2009 a) isinserted through bore 2008 a, for example, the instrument's distalportion, which is larger than its proximal body segment, passes throughat least part of slot 2008 c and possibly some or all of bore 2008 b.FIG. 19H illustrates this aspect. Once the instrument's distal portionhas been inserted beyond the guide tube's distal end, the instrument'sproximal body segment is rotated within bore 2008 a, which holds theproximal body segment in place. Consequently, another instrument(illustrated by the circular dashed line 2009 b), either cylindrical orwith an enlarged distal portion that fits through slot 2008 c, can beinserted through bore 2008 b. This channel configuration and insertionprocess can be used for various instruments with odd-shaped distalportions, such as staplers, clip appliers, and other special taskinstruments, as well as for the retrograde working instruments describedherein. In addition, an imaging device having a distal image capturecomponent cross section larger than its body cross section and shaped topass through the channel's oblong cross section may be similarlyinserted, followed by one or more other instruments. The lip 2011 ofchannel 2008, or any channel, is in some instances rounded or beveled asshown to facilitate instrument withdrawal into the guide tube.

FIG. 20B is an end elevation view of the distal end face of guide tube2002 with an illustrative imaging system 2010 and two surgicalinstruments 2012,2014, all extending from their insertion channels2004,2008. Instrument 2012 is a U-Turn mechanism type retrograde workinginstrument, similar to the illustrative embodiment shown in FIGS. 19 and19A. Instrument 2014 is generally circular in cross section duringinsertion, although during insertion a portion of instrument 2014 mayextend into any portion of slot 2008 c that instrument 2012 does notoccupy. As another example, an instrument with the multiple cable guidetube U-Turn mechanism, similar to the embodiments shown in FIGS.19B-19I, may be inserted through channel 2008, with the body and distalportions of the instrument passing through the bores and the pinchedportion of the U-Turn mechanism passing through the slot between thebores.

The channel topography illustrated in FIG. 20A can be adapted to allow,e.g., two instruments with large distal ends to be inserted through aguide tube, possibly adding a third instrument as well. FIG. 20C is anend elevation view that illustrates aspects in which an instrumentchannel includes bores arranged in a “V” shape, although the “V” may beflattened so that three or more channel bores are side-by-side in aline. As shown, channel 2020 includes three cylindrical bores 2020a,2020 b,2020 c, with slot 2020 d joining bores 2020 a and 2020 b, andslot 2020 e joining bores 2020 b and 2020 c. Bores 2020 a and 2020 c areshown at the ends of the “V” shape, and bore 2020 b is shown at thevertex of the “V” shape. Illustratively, a first retrograde workinginstrument with a U-Turn mechanism is inserted via bores 2020 a and 2020b, and then a second retrograde working instrument with a U-Turnmechanism is inserted via bores 2020 c and 2020 b. Once inserted, thethree bores allow either of the instruments to be independentlyremoved—one instrument does not have to be removed to allow the otherinstrument to be removed. An optional third instrument may be insertedvia bore 2020 b once two other instruments are inserted with theirproximal body segments held in place within bores 2020 a and 2020 c. Itcan be seen that two large-ended instruments and an optional thirdinstrument may be inserted via channel 2020 in various combinations. Animaging system may be inserted via channel 2022, which may be a roundedrectangle as shown, circular, or various other shapes as illustratedherein (e.g., 2004 in FIG. 20A). Alternatively, if an imaging system hasa suitably shaped distal end, it may be inserted via channel 2020. Anassembly with two retrograde working instruments and an imaging systemis illustrated in FIG. 19J.

FIGS. 20D, 20E, and 20F are each end elevation views that illustrateaspects of other channel configurations that may be used to accommodateone or more instruments with large distal ends. FIG. 20D shows channel2030 with three bores 2030 a,2030 b,2030 c in a triangular arrangement.The slots that interconnect adjacent bores merge into a single openingthat connects each bore with the other two (i.e., the top of the “V”shape illustrated in FIG. 20C is joined by a third slot. The channel hasa generally triangular cross section, and the bores are at thetriangle's vertices). Also shown is an illustrative spacer 2032, showncentered in channel 2030, which helps keep the instrument bodies intheir bores or positioned at their vertexes if the channel sides betweenthe bores are not sufficiently pinched to hold the instrument bodies inplace within the bores. FIG. 20E illustrates that the channel can haveany number of bores to accept surgical instruments (four are shown withthe bores arranged at the corners of a square). FIG. 20F illustrates achannel with a “T” shape, the bores for the instruments being the threeends of the “T”. A spacer such as shown in FIG. 20D may be used to keepinstruments properly positioned within the “T”, or the connectingopenings between the bores may be slightly pinched to keep theinstruments in their bores. Other cross-sectional channel shapes (e.g.,a cross or “X” shape; it can be seen that a “T” shape is part of such across or “X” shape) may be used with a cross-sectional configuration ora separate component that keeps a surgical instrument's body or shaft inplace within the channel.

In FIGS. 20A-20F, the bores that hold the proximal segments of theinstrument and imaging system bodies are shown as circular, which allowsthe bodies to roll within the bores. In some aspects, however, some orall the bores may have non-circular cross sections to prevent the bodysegments from rolling within the bores. For example, one non-circularbore may be dedicated to holding the proximal body segment of an imagingsystem, which is kept from rolling. Or, specifically shaped bores may beused to ensure that only a particular device may be inserted into aparticular bore. In some aspects, however, any surgical instrument orimaging system may be inserted via any bore.

Support and Control Aspects

FIG. 21A is a schematic view that illustrates aspects of arobot-assisted (telemanipulative) minimally invasive surgical systemthat uses aspects of the minimally invasive surgical instruments,instrument assemblies, and manipulation and control systems describedherein. This system's general architecture is similar to thearchitecture of other such systems such as Intuitive Surgical, Inc.'s daVinci® Surgical System and the Zeus® Surgical System. The three maincomponents are a surgeon's console 2102, a patient side support system2104, and a video system 2106, all interconnected 2108 by wired orwireless connections as shown. One or more electronic data processorsmay be variously located in these main components to provide systemfunctionality.

The surgeon's console 2102 includes, e.g., multiple DOF mechanical input(“master”) devices that allow the surgeon to manipulate the surgicalinstruments, guide tubes, and imaging system (“slave”) devices asdescribed herein. These input devices may in some aspects provide hapticfeedback from the instruments and instrument assembly components to thesurgeon. Console 2102 also includes a stereoscopic video output displaypositioned such that images on the display are generally focused at adistance that corresponds to the surgeon's hands working behind/belowthe display screen. These aspects are discussed more fully in U.S. Pat.No. 6,671,581, which is incorporated by reference above. Control duringinsertion may be accomplished, for example, in a manner similar totelemanipulated endoscope control in the da Vinci® Surgical System—inone aspect the surgeon virtually moves the image with one or both of themasters; she uses the masters to move the image side to side and to pullit towards herself, consequently commanding the imaging system and itsassociated instrument assembly (e.g., a flexible guide tube) to steertowards a fixed center point on the output display and to advance insidethe patient. In one aspect the camera control is designed to give theimpression that the masters are fixed to the image so that the imagemoves in the same direction that the master handles are moved, as in theda Vinci® surgical system. This design causes the masters to be in thecorrect location to control the instruments when the surgeon exits fromcamera control, and consequently it avoids the need to clutch(disengage), move, and declutch (engage) the masters back into positionprior to beginning or resuming instrument control. In some aspects themaster position may be made proportional to the insertion velocity toavoid using a large master workspace. Alternatively, the surgeon mayclutch and declutch the masters to use a ratcheting action forinsertion. In some aspects, insertion (e.g., past the glottis whenentering via the esophagus) may be controlled manually (e.g., by handoperated wheels), and automated insertion (e.g., servomotor drivenrollers) is then done when the distal end of the surgical instrumentassembly is near the surgical site. Preoperative or real time image data(e.g., MRI, X-ray) of the patient's anatomical structures and spacesavailable for insertion trajectories may be used to assist insertion.

The patient side support system 2104 includes a floor-mounted base 2110,or alternately a ceiling mounted base 2112 as shown by the alternatelines. The base may be movable or fixed (e.g., to the floor, ceiling, orother equipment such as an operating table). In one embodiment themanipulator arm assembly is a modified da Vinci® Surgical System armassembly. The arm assembly includes two illustrative passive rotationalsetup joints 2114 a,2114 b, which allow manual positioning of thecoupled links when their brakes are released. A passive prismatic setupjoint (not shown) between the arm assembly and the base may be used toallow for large vertical adjustments. In addition, the arm assemblyincludes illustrative active roll joint 2116 a and active yaw joint 2116b. Joints 2116 c and 2116 d act as a parallel mechanism so that a guidetube (of a surgical instrument assembly) held by guide manipulator 2118moves around remote center 2120 at an entry port such as patient 1222'sumbilicus. An active prismatic joint 2124 is used to insert and withdrawthe guide tube. One or more surgical instruments and an endoscopicimaging system are independently mounted to guide manipulator 2118. Thevarious setup and active joints allow the manipulators to move the guidetube, instruments, and imaging system when patient 2122 is placed invarious positions on movable table 2126.

FIGS. 21B and 21C are schematic side and front elevation views ofanother illustrative embodiment of a patient side support system. Base2150 is fixed (e.g., floor or ceiling mounted). Link 2152 is coupled tobase 2150 at passive rotational setup joint 2154. As shown, joint 2154'srotational axis is aligned with remote center point 2156, which isgenerally the position at which a guide tube (of a surgical instrumentassembly; not shown) enters the patient (e.g., at the umbilicus forabdominal surgery). Link 2158 is coupled to link 2152 at rotationaljoint 2160. Link 2162 is coupled to link 2158 at rotational joint 2164.Link 2166 is coupled to link 2162 at rotational joint 2168. The guidetube is mounted to slide through the end 2166 a of link 2166.Manipulator platform 2170 is supported and coupled to link 2166 by aprismatic joint 2172 and a rotational joint 2174. Prismatic joint 2172inserts and withdraws the guide tube as it slides along link 2166. Joint2174 includes a bearing assembly that holds a “C” shaped ringcantilever. As the “C” ring slides through the bearing it rotates arounda center point inside the “C”, thereby rolling the guide tube. Theopening in the “C” allows guide tubes to be mounted or exchanged withoutmoving overlying manipulators. Manipulator platform 2170 supportsmultiple manipulators 2176 for surgical instruments and an imagingsystem, described below.

These illustrative manipulator arm assemblies are used, for example, forinstrument assemblies that include a rigid guide tube and are operatedto move with reference to a remote center. Certain setup and activejoints in the manipulator arm may be omitted if motion around a remotecenter is not required. It should be understood that manipulator armsmay include various combinations of links, passive, and active joints(redundant DOFs may be provided) to achieve a necessary range of posesfor surgery.

Referring again to FIG. 21A, video system 2106 performs image processingfunctions for, e.g., captured endoscopic imaging data of the surgicalsite and/or preoperative or real time image data from other imagingsystems external to the patient. Imaging system 2106 outputs processedimage data (e.g., images of the surgical site, as well as relevantcontrol and patient information) to the surgeon at the surgeon's console2102. In some aspects the processed image data is output to an optionalexternal monitor visible to other operating room personnel or to one ormore locations remote from the operating room (e.g., a surgeon atanother location may monitor the video; live feed video may be used fortraining; etc.).

FIG. 22A is a diagrammatic view that illustrates aspects of acentralized motion control and coordination system architecture forminimally invasive telesurgical systems that incorporate surgicalinstrument assemblies and components described herein. A motioncoordinator system 2202 receives master inputs 2204, sensor inputs 2206,and optimization inputs 2208.

Master inputs 2204 may include the surgeon's arm, wrist, hand, andfinger movements on the master control mechanisms. Inputs may also befrom other movements (e.g., finger, foot, knee, etc. pressing or movingbuttons, levers, switches, etc.) and commands (e.g., voice) that controlthe position and orientation of a particular component or that control atask-specific operation (e.g., energizing an electrocautery end effectoror laser, imaging system operation, and the like).

Sensor inputs 2206 may include position information from, e.g., measuredservomotor position or sensed bend information. U.S. patent applicationSer. No. 11/491,384 (Larkin, et al.) entitled “Robotic surgery systemincluding position sensors using fiber Bragg gratings”, incorporated byreference, describes the use of fiber Bragg gratings for positionsensing. Such bend sensors may be incorporated into the variousinstruments and imaging systems described herein to be used whendetermining position and orientation information for a component (e.g.,an end effector tip). Position and orientation information may also begenerated by one or more sensors (e.g., fluoroscopy, MRI, ultrasound,and the like) positioned outside of the patient and which in real timesense changes in position and orientation of components inside thepatient.

As described below, the user interface has three coupled control modes:a mode for the instrument (s), a mode for the imaging system, and a modefor the guide tube. These coupled modes enable the user to address thesystem as a whole rather than directly controlling a single portion.Therefore, the motion coordinator must determine how to take advantageof the overall system kinematics (i.e., the total DOFs of the system) inorder to achieve certain goals. For example, one goal may be to optimizeinstrument workspace for a particular configuration. Another goal may beto keep the imaging system's field of view centered between twoinstruments. Therefore, optimization inputs 2208 may be high-levelcommands, or the inputs may include more detailed commands or sensoryinformation. An example of a high level command would be a command to anintelligent controller to optimize a workspace. An example of a moredetailed command would be for an imaging system to start or stopoptimizing its camera. An example of a sensor input would be a signalthat a workspace limit had been reached.

Motion coordinator 2202 outputs command signals to various actuatorcontrollers and actuators (e.g., servomotors) associated withmanipulators for the various telesurgical system arms. FIG. 22A depictsan example of output signals being sent to two instrument controllers2210, to an imaging system controller 2212, and to a guide tubecontroller 2214. Other numbers and combinations of controllers may beused.

As an example, such a motion coordination system may be used to controlsurgical instrument assembly 1700 (FIG. 17). Instrument controllers 2210are associated with instruments 1702 a,1702 b, imaging system controller2212 is associated with imaging system 1704, and guide tube controller2214 is associated with guide tube 1708. Accordingly, in some aspectsthe surgeon who operates the telesurgical system will simultaneously andautomatically access at least the three control modes identified above:an instrument control mode for moving the instruments, an imaging systemcontrol mode for moving the imaging system, and a guide tube controlmode for moving the guide tube. A similar centralized architecture maybe adapted to work with the various other mechanism aspects describedherein.

FIG. 22B is a diagrammatic view that illustrates aspects of adistributed motion control and coordination system architecture forminimally invasive telesurgical systems that incorporate surgicalinstrument assemblies and components described herein. In theillustrative aspects shown in FIG. 223, control and transform processor2220 exchanges information with two master arm optimizer/controllers2222 a,2222 b, with three surgical instrument optimizer/controllers 2224a,2224 b,2224 c, with an imaging system optimizer/controller 2226, andwith a guide tube optimizer/controller 2228. Each optimizer/controlleris associated with a master or slave arm (which includes, e.g., thecamera (imaging system) arm, the guide tube arm, and the instrumentarms) in the telesurgical system. Each of the optimizer/controllersreceives arm-specific optimization goals 2230 a-2230 g.

The double-headed arrows between control and transform processor 2220and the various optimizer/controllers represents the exchange ofFollowing Data associated with the optimizer/controller's arm. FollowingData includes the full Cartesian configuration of the entire arm,including base frame and distal tip frame. Control and transformprocessor 2220 routes the Following Data received from eachoptimizer/controller to all the optimizer/controllers so that eachoptimizer/controller has data about the current Cartesian configurationof all arms in the system. In addition, the optimizer/controller foreach arm receives optimization goals that are unique for the arm. Eacharm's optimizer/controller then uses the other arm positions as inputsand constraints as it pursues its optimization goals. In one aspect,each optimization controller uses an embedded local optimizer to pursueits optimization goals. The optimization module for each arm'soptimizer/controller can be independently turned on or off. For example,the optimization module for only the imaging system and the guide tubemay be turned on.

The distributed control architecture provides more flexibility than thecentralized architecture, although with the potential for decreasedperformance. It easier to add in a new arm and to change the overallsystem configuration if such a distributed control architecture is usedrather than if a centralized architecture is used. In this distributedarchitecture, however, the optimization is local versus the globaloptimization that can be performed with the centralized architecture, inwhich a single module is aware of the full system's state.

FIG. 23 is a schematic view that illustrates aspects of an interfacebetween surgical instrument assembly 2302, which represents flexible andrigid mechanisms as variously described herein, and an illustrativeactuator assembly 2304. For the purposes of this example, instrumentassembly 2302 includes surgical instrument 2306, primary guide tube 2308that surrounds instrument 2306, and secondary guide tube 2310 thatsurrounds primary guide tube 2308.

As shown in FIG. 23, a transmission mechanism is positioned at theproximal ends of each instrument or guide tube: transmission mechanism2306 a for instrument 2306, transmission mechanism 2308 a for primaryguide tube 2308, and transmission mechanism 2310 a for secondary guidetube 2310. Each transmission mechanism is mechanically and removablycoupled to an associated actuator mechanism: transmission mechanism 2306a to actuator mechanism 2312, transmission mechanism 2308 a to actuatormechanism 2314, transmission mechanism 2310 a to actuator mechanism2316. In one aspect, mating disks are used as in the da Vinci® SurgicalSystem instrument interface, as shown in more detail below. In anotheraspect, mating gimbal plates and levers are used. Various mechanicalcomponents (e.g., gears, levers, cables, pulleys, cable guides, gimbals,etc.) in the transmission mechanisms are used to transfer the mechanicalforce from the interface to the controlled element. Each actuatormechanism includes at least one actuator (e.g., servomotor (brushed orbrushless)) that controls movement at the distal end of the associatedinstrument or guide tube. For example, actuator 2312 a is an electricservomotor that controls surgical instrument 2306's end effector 2306 bgrip DOF. An instrument (including a guide probe as described herein) orguide tube (or, collectively, the instrument assembly) may be decoupledfrom the associated actuator mechanism(s) and slid out as shown. It maythen be replaced by another instrument or guide tube. In addition to themechanical interface there is an electronic interface between eachtransmission mechanism and actuator mechanism. This electronic interfaceallows data (e.g., instrument/guide tube type) to be transferred.

In some instances one or more DOFs may be manually actuated. Forinstance, surgical instrument 2306 may be a passively flexiblelaparoscopic instrument with a hand-actuated end effector grip DOF, andguide tube 2308 may be actively steerable to provide wrist motion asdescribed above. In this example, the surgeon servocontrols the guidetube DOFs and an assistant hand controls the instrument grip DOF.

In addition to the actuators that control the instrument and/or guidetube elements, each actuator assembly may also include an actuatorcomponent (e.g., motor-driven cable, lead screw, pinion gear, etc.;linear motor; and the like) that provides motion along instrumentassembly 2302's longitudinal axis (surge). As shown in the FIG. 23example, actuator mechanism 2312 includes linear actuator 2312 b,actuator mechanism 2314 includes linear actuator 2314 b, and actuatormechanism 2316 includes linear actuator 2316 b, so that instrument 2306,primary guide tube 2308, and secondary guide tube 2310 can each beindependently coaxially moved. As further shown in FIG. 23, actuatorassembly 2316 is mounted to setup arm 2318, either passively or activelyas described above. In active mounting architectures, the activemounting may be used to control one or more component DOFs (e.g.,insertion of a rigid guide tube).

Control signals from control system 2320 control the various servomotoractuators in actuator assembly 2304. The control signals are, e.g.,associated with the surgeon's master inputs at input/output system 2322to move instrument assembly 2302's mechanical slave components. In turn,various feedback signals from sensors in actuator assembly 2304, and/orinstrument assembly 2302, and/or other components are passed to controlsystem 2320. Such feedback signals may be pose information, as indicatedby servomotor position or other position, orientation, and forceinformation, such as may be obtained with the use of fiber Bragggrating-based sensors. Feedback signals may also include force sensinginformation, such as tissue reactive forces, to be, e.g., visually orhaptically output to the surgeon at input/output system 2322.

Image data from an endoscopic imaging system associated with instrumentassembly 2302 are passed to image processing system 2324. Such imagedata may include, e.g., stereoscopic image data to be processed andoutput to the surgeon via input/output system 2322 as shown. Imageprocessing may also be used to determine instrument position, which isinput to the control system as a form of distal position feedbacksensor. In addition, an optional sensing system 2326 positioned outsideand near the patient may sense position or other data associated withinstrument assembly 2302. Sensing system 2326 may be static or may becontrolled by control system 2320 (the actuators are not shown, and maybe similar to those depicted or to known mechanical servo components)and it may include one or more actual sensors positioned near thepatient. Position information (e.g., from one or more wirelesstransmitters, RFID chips, etc.) and other data from sensing system 2326may be routed to control system 2320. If such position information orother data is to be visually output to the surgeon, control system 2320passes it in either raw or processed form to image processing system2324 for integration with the surgeon's output display at input/outputsystem 2322. Further, any image data, such as fluoroscopic or otherreal-time imaging (ultrasound, X-ray, MRI, and the like), from sensingsystem 2326 are sent to image processing system 2324 for integrationwith the surgeon's display. And, real-time images from sensing system2326 may be integrated with preoperative images accessed by imageprocessing system 2324 for integration with the surgeon's display. Inthis way, for instance, preoperative images of certain tissue (e.g.,brain tissue structures) are received from a data storage location 2328,may be enhanced for better visibility, the preoperative images areregistered with other tissue landmarks in real time images, and thecombined preoperative and real time images are used along with positioninformation from instrument and actuator assemblies 2302,2304 and/orsensing system 2326 to present an output display that assists thesurgeon to maneuver instrument assembly 2302 towards a surgical sitewithout damaging intermediate tissue structures.

FIG. 24A is a perspective view of the proximal portion of a minimallyinvasive surgical instrument 2402. As shown in FIG. 24A, instrument 2402includes a transmission mechanism 2404 coupled to the proximal end of aninstrument body tube 2406. Components at body tube 2406's distal end2408 are omitted for clarity and may include, e.g., the 2 DOF parallelmotion mechanism, wrist, and end effector combination as describedabove; joints and an endoscopic imaging system as described above; etc.In the illustrative embodiment shown, transmission mechanism 2404includes six interface disks 2410. One or more disks 2410 are associatedwith a DOF for instrument 240. For instance, one disk may be associatedwith instrument body roll DOF, and a second disk may be associated withend effector grip DOF. As shown, in one instance the disks are arrangedin a hexagonal lattice for compactness—in this case six disks in atriangular shape. Other lattice patterns or more arbitrary arrangementsmay be used. Mechanical components (e.g., gears, levers, gimbals,cables, etc.) inside transmission mechanism 2404 transmit roll torqueson disks 2410 to e.g., body tube 2406 (for roll) and to componentscoupled to distal end mechanisms. Cables and/or cable and hypotubecombinations that control distal end DOFs run through body tube 2406. Inone instance the body tube is approximately 7 mm in diameter, and inanother instance it is approximately 5 mm in diameter. Raised pins 2412,spaced eccentrically, provide proper disk 2410 orientation when matedwith an associated actuator disk. One or more electronic interfaceconnectors 2414 provide an electronic interface between instrument 2402and its associated actuator mechanism. In some instances instrument 2402may pass information stored in a semiconductor memory integrated circuitto the control system via its associated actuator mechanism. Such passedinformation may include instrument type identification, number ofinstrument uses, and the like. In some instances the control system mayupdate the stored information (e.g., to record number of uses todetermine routine maintenance scheduling or to prevent using aninstrument after a prescribed number of times). U.S. Pat. No. 6,866,671(Tierney et al.), which discusses storing information on instruments, isincorporated by reference. The electronic interface may also includepower for, e.g., an electrocautery end effector. Alternately, such apower connection may be positioned elsewhere on instrument 2402 (e.g.,on transmission mechanism 2404's housing). Other connectors for, e.g.,optical fiber lasers, optical fiber distal bend or force sensors,irrigation, suction, etc. may be included. As shown, transmissionmechanism 2404's housing is roughly wedge- or pie-shaped to allow it tobe closely positioned to similar housings, as illustrated below.

FIG. 24B is a perspective view of a portion of an actuator assembly 2420that mates with and actuates components in surgical instrument 2402.Actuator disks 2422 are arranged to mate with interface disks 2410.Holes 2424 in disks 2422 are aligned to receive pins 2412 in only asingle 360-degree orientation. Each disk 2422 is turned by an associatedrotating servomotor actuator 2426, which receives servocontrol inputs asdescribed above. A roughly wedge-shaped mounting bracket 2428, shaped tocorrespond to instrument 2402's transmission mechanism housing, supportsthe disks 2422, servomotor actuators 2426, and an electronic interface2430 that mates with instrument 2402's interface connectors 2414. In oneinstance instrument 2402 is held against actuator assembly 2420 byspring clips (not shown) to allow easy removal. As shown in FIG. 24B, aportion 2432 of actuator assembly housing 2428 is truncated to allowinstrument body tube 2406 to pass by. Alternatively, a hole may beplaced in the actuator assembly to allow the body tube to pass through.Sterilized spacers (reusable or disposable; usually plastic) may be usedto separate the actuator assembly and the instrument's transmissionmechanism to maintain a sterile surgical field. A sterile thin plasticsheet or “drape” (e.g., 0.002-inch thick polyethylene) is used to coverportions of the actuator assembly not covered by the spacer, as well asto cover portions of the manipulator arm. U.S. Pat. No. 6,866,671,incorporated by reference above, discusses such spacers and drapes.

FIG. 25A is a diagrammatic perspective view that illustrates aspects ofmounting minimally invasive surgical instruments and their associatedactuator assemblies at the end of a setup/manipulator arm. As shown inFIG. 25A, surgical instrument 2502 a is mounted on actuator assembly2504, so that the transmission mechanism mates with the actuatorassembly (optional spacer/drape is not shown) as described above.Instrument 2502 a's body tube 2506 extends past actuator assembly 2504and enters a port in rigid guide tube 2508. As depicted, body tube 2506,although substantially rigid, is bent slightly between the transmissionmechanism housing and the guide tube as discussed above with referenceto FIG. 16. This bending allows the instrument body tube bores in theentry guide to be spaced closer than the size of their transmissionmechanisms would otherwise allow. Since the bend angle in the rigidinstrument body tube is less than the bend angle for a flexible (e.g.,flaccid) instrument body, cables can be stiffer than in a flexible body.High cable stiffness is important because of the number of distal DOFsbeing controlled in the instrument. Also, the rigid instrument body iseasier to insert into a guide tube than a flexible body. In oneembodiment the bending is resilient so that the body tube assumes itsstraight shape when the instrument is withdrawn from the guide tube (thebody tube may be formed with a permanent bend, which would preventinstrument body roll). Actuator assembly 2504 is mounted to a linearactuator 2510 (e.g. a servocontrolled lead screw and nut or a ball screwand nut assembly) that controls body tube 2506's insertion within guidetube 2508. The second instrument 2502 b is mounted with similarmechanisms as shown. In addition, an imaging system (not shown) may besimilarly mounted.

FIG. 25A further shows that guide tube 2508 is removably mounted tosupport platform 2512. This mounting may be, for example, similar to themounting used to hold a cannula on a da Vinci® Surgical Systemmanipulator arm. Removable and replaceable guide tubes allow differentguide tubes that are designed for use with different procedures to beused with the same telemanipulative system (e.g., guide tubes withdifferent cross-sectional shapes or various numbers and shapes ofworking and auxiliary channels). In turn, actuator platform 2512 ismounted to robot manipulator arm 2514 (e.g., 4 DOF) using one or moreadditional actuator mechanisms (e.g., for pitch, yaw, roll, insertion).In turn, manipulator arm 2514 may be mounted to a passive setup arm, asdescribed above with reference to FIG. 21A.

FIG. 25B is a diagrammatic perspective view that illustrates aspectsshown in FIG. 25A from a different angle and with reference to apatient. In FIG. 2B, arm 2514 and platform 2512 are positioned so thatguide tube 2508 enters the patient's abdomen at the umbilicus. Thisentry is illustrative of various natural orifice and incision entries,including percutaneous and transluminal (e.g., transgastric,transcolonic, transrectal, transvaginal, transrectouterine (Douglaspouch), etc.) incisions. FIG. 25B also illustrates how the linearactuators for each instrument/imaging system operate independently byshowing imaging system 2518 inserted and instruments 2502 a,2502 bwithdrawn. These aspects may apply to other surgical instrumentassemblies described herein (e.g., flexible guide tubes with end- orside-exit ports, side working tools, etc.). It can be seen that in someinstances the manipulator arm moves to rotate guide tube 2508 around aremote center 2520 at the entry port into a patient. If intermediatetissue restricts movement around a remote center, however, the arm canmaintain guide tube 2508 in position.

As discussed above, in one aspect the instruments and their transmissionmechanisms are arranged around a guide tube in a generally pie-wedgelayout as shown in FIG. 26A, which is a diagrammatic end view ofinstrument transmission mechanisms and a guide tube (the vertices of thewedge shapes are oriented towards an extended centerline of the guidetube). The vertices of the wedge shapes are shown slightly truncated;the wedge shape should be understood to be broadly construed and toinclude both acute and obtuse vertex angles. Instrument transmissionmechanisms 2602 a,2602 b transfer control forces from servomotors toinstruments inserted via guide tube 2604's working channels 2606 a,2606b. Imaging system transmission mechanism 2608 transfers control forcesfrom servomotors to the multi-DOF imaging system instrument inserted viaguide tube 2604's imaging system channel 2606 c. One or more optionalguide tube channels 2604 d allow for manually inserting an instrument,irrigation, suction, etc. FIGS. 26B and 26C are similar diagrammatic endviews and illustrate that transmission mechanisms may be spaced aroundthe guide tube in other configurations, such as four wedges 2608 spaced360-degrees around the guide tube (FIG. 26B), or two half-circle shapedhousings 2610 (FIG. 26C). It can also be seen from the aspectsillustrated in FIGS. 25A, 25B, 26A, 26B, and 26C that transmissionassemblies can not only be spaced around the guide tube but can bestacked one above or behind the other as FIG. 23 schematicallyillustrates. FIG. 26D is another diagrammatic end view that illustratesthat actuator mechanisms 2620 may be placed farther from guide tube2622's extended centerline than the instrument/guide tube and imagingsystem transmission mechanisms 2624.

FIG. 26E is a diagrammatic exploded perspective view that illustratesthat actuator mechanisms for more than one component may be placed in asingle housing. As shown in FIG. 26E, actuator mechanism housing 2630includes servomotors and associated components (not shown) used to moveguide tube 2632. Housing 2630 also includes servomotors and associatedcomponents used to operate instrument 2634. Instrument 2634's body anddistal segments are inserted through housing 2630 as shown, andinterface components 2636 on housing 2630 connect with correspondingcomponents (e.g., disks 2410 (FIG. 24)) on instrument 2634. Such anarrangement may be used for, e.g., the side exit surgical instrumentassemblies described herein, in which there are two housings 2634, eachassociated with one of the side exiting instruments or guide tubes.

Details about the mechanical and electrical interfaces for the variousinstruments, guide tubes, and imaging systems, and also about steriledraping to preserve the sterile field, are discussed in U.S. Pat. No.6,866,671 (Tierney et al.) and U.S. Pat. No. 6,132,368 (Cooper), both ofwhich are incorporated by reference. Mechanical interface mechanisms arenot limited to the disks shown and described. Other mechanisms such asrocking plates, gimbals, moving pins, levers, cable latches, and otherremovable couplings may be used.

FIG. 27 is a diagrammatic view that illustrates aspects of transmissionmechanisms associated with flexible coaxial guide tubes and instruments.FIG. 27 shows primary guide tube 2702 running coaxially through andexiting the distal end of secondary guide tube 2704. Likewise, secondaryguide tube 2704 runs coaxially through and exits the distal end oftertiary guide tube 2706. Transmission and actuator mechanism 2708 isassociated with tertiary guide tube 2706. Transmission and actuatormechanism 2710 is associated with secondary guide tube 2704, and aproximal segment of guide tube 2704 extends through (alternatively,adjacent to) transmission and actuator mechanism 2710 before enteringtertiary guide tube 2706. Likewise, transmission and actuator mechanism2712 is associated with primary guide tube 2702, and a proximal segmentof guide tube 2702 extends through (alternatively, adjacent to)transmission and actuator mechanisms 2708,2710 before entering secondaryand tertiary guide tubes 2704,2706. Transmission mechanisms forinstruments and an imaging system (not shown) running through andexiting the distal ends of channels 2714 in primary guide tube 2702 maybe similarly stacked generally along the instrument assembly'slongitudinal axis, or they may be arranged around guide tube 2702'sextended longitudinal axis at its proximal end as described above. Or,the controller positions may be combined side-by-side and stacked, suchas for a side-exit assembly in which transmission mechanisms for theside-exiting components are positioned side-by-side, and both arestacked behind the guide tube transmission mechanism. Intermediate exitassemblies may be similarly configured. Instrument and/or imaging systemactuators and controls may also be combined within the same housing asan actuator and transmission mechanism for a guide tube.

In many aspects the devices described herein are used as single-portdevices—all components necessary to complete a surgical procedure enterthe body via a single entry port. In some aspects, however, multipledevices and ports may be used. FIG. 28A is a diagrammatic view thatillustrates multi-port aspects as three surgical instrument assembliesenter the body at three different ports. Instrument assembly 2802includes a primary guide tube, a secondary guide tube, and twoinstruments, along with associated transmission and actuator mechanisms,as described above. In this illustrative example, instrument assembly2804 includes a primary guide tube, a secondary guide tube, and a singleinstrument, along with associated transmission and actuator mechanisms,as described above. Imaging system assembly 2806 includes a guide tubeand an imaging system, along with associated transmission and actuatormechanisms, as described above. Each of these mechanisms 2802,2804,2806enters the body 2808 via a separate, unique port as shown. The devicesshown are illustrative of the various rigid and flexible aspectsdescribed herein.

FIG. 28B is another diagrammatic view that illustrates multi-portaspects. FIG. 28B shows three illustrative instruments or assemblies2810 entering different natural orifices (nostrils, mouth) and thencontinuing via a single body lumen (throat) to reach a surgical site.

FIGS. 29A and 29B are diagrammatic views that illustrate further aspectsof minimally invasive surgical instrument assembly position sensing andmotion control. As shown in FIG. 29A, the distal end 2902 of a surgicalinstrument device or assembly is advanced within the walls 2904 of abody lumen or other cavity towards surgical site 2906. Distal end 2902is illustrative of various components, such as a guide probe or guidetube as described above. As distal end 2902 advances it is moved (flexedas shown, or pivoted at a joint) up and down and side to side, asdepicted by the alternate position lines. As the tip of distal end 2902touches, or comes close to touching, a position on walls 2904, actuatorcontrol system 2908 records the tip's position and stores the positiondata in memory 2910. Tip position information may come directly from thesurgical instrument assembly or from an external sensor 2912, asdescribed above. The tip may be bent in various 3-dimensional directionsso that it touches or nearly touches walls 2904 in various patterns(e.g., a series of rings, a helix, a series of various crosses or stars,etc.), either under a surgeon's direct control or under automaticcontrol by control system 2908. Once the lumen's or cavity's interiorspace is mapped, the space information is used to assist advancingsubsequent surgical instrument assembly components, as illustrated inFIG. 29B. As an example, a secondary guide tube 2912 with side exitports is shown, and control system 2908 uses the map information toprevent primary guide tubes 2914 a,2914 b and their associated endeffectors from interfering with walls 2904 as they are advanced towardssurgical site 2906.

FIGS. 29C-29E are diagrammatic plan views that illustrate furtheraspects of preventing undesired instrument collision with tissue.Instruments may collide with patient tissue outside of an imagingsystem's field of view in spaces confined by patient anatomy (e.g.,laryngeal surgery). Such collisions may damage tissue. For multi-DOFsurgical instruments, some DOFs may be inside the field of view whileother, more proximal DOFs may be outside the field of view.Consequently, a surgeon may be unaware that tissue damage is occurringas these proximal DOFs move. As shown in FIG. 29C, for example, anendoscopic imaging system 2920 extends from the end of guide tube 2922.The left side working instrument 2924 a is placed so that all DOFs arewithin imaging system 2920's field of view 2926 (bounded by the dashedlines). The right side working instrument 2924 b, however, has proximalDOFs (an illustrative parallel motion mechanism as described above andwrist are shown) that are outside field of view 2926, even thoughinstrument 2924 b's end effector is within field of view 2926. Thisinstrument position is illustrative of tasks such as tying sutures.

In one aspect, field of view boundaries can be determined when thecamera is manufactured so that the boundaries are known in relation tothe camera head (image capture component). The boundary information isthen stored in a nonvolatile memory associated with the imaging systemthat incorporates the camera head. Consequently, the control system canuse the imaging system instrument's kinematic and joint positioninformation to locate the camera head relative to the workinginstruments, and therefore the control system can determine the field ofview boundaries relative to the working instruments. Instruments arethen controlled to work within the boundaries.

In another aspect for stereoscopic imaging systems, field of viewboundaries can be determined relative to the instruments by usingmachine vision algorithms to identify the instruments and theirpositions in the field of view. This “tool tracking” subject isdisclosed in U.S. Patent Application Publication No. US 2006/0258938 A1(Hoffman et al.), which is incorporated by reference.

As shown in FIG. 29D, imaging system 2920 is placed so that the camerahead is just at the distal end of guide tube 2922. Instruments 2924 aand 2924 b are extended from the distal end of the guide tube and withinimaging system 2920's field of view. An “Allowable Volume” is defined tobe coincident with the field of view boundaries. The control systemprevents any part of instruments 2924 a and 2924 b from moving outsidethe Allowable Volume. Since the surgeon can see all distal moving partsof instruments 2924 a and 2924 b, the surgeon then moves the instrumentswithout colliding with surrounding tissue. The instrument movements arerecorded, and an “Instrument Volume” 2928 (bounded by the dotted lines),which is bounded by the farthest movements of the instruments, isdetermined. The Instrument Volume is a convex volume within whichinstruments may be moved without colliding with tissue.

Next, imaging system 2920 is inserted as shown in FIG. 29E. As a result,field of view 2926 is also inserted, and parts of instruments 2924a,2924 b are outside of the inserted field of view 2926. A new AllowableVolume is determined to be the newly inserted field of view plus thepreviously determined Instrument Volume that is outside of the field ofview. Therefore, the control system will allow the surgeon to move aninstrument anywhere within the new Allowable Volume. The process may berepeated for further field of view insertions or for guide tube 2922movements. This scheme allows a surgeon to define the allowableinstrument range of motion in real time without requiring a tissuemodel. The surgeon is only required to trace the boundaries of theinstrument range of motion inside the field of view, and the controlsystem will record this information as the field of view is changed.

Another way to prevent unwanted instrument/tissue collision is by usingimage mosaicing. FIG. 29F is a diagrammatic view of a display (e.g.,stereoscopic) that a surgeon sees during a surgical procedure. As shownin FIG. 29F, the image from the new, more inserted field of view 2940(bounded by the dashed lines) is registered and mosaiced with the imagefrom the old, more withdrawn field of view 2942. Image mosaicing isknown (see e.g., U.S. Pat. No. 4,673,988 (Jansson et al.) and U.S. Pat.No. 5,999,662 (Burt et al.), which are incorporated by reference) andhas been applied to medical equipment (see e.g., U.S. Pat. No. 7,194,118(Harris et al.), which is incorporated by reference). As a result, thesurgeon sees an area larger than the current, more inserted field ofview. A kinematically accurate graphical simulation of the instrumentsis shown in the old field of view 2942 so that the surgeon can seepossible collisions in this region as the instruments move.

In some aspects, minimally invasive surgical instrument assemblycomponents may be replaced by hand during surgery. In other aspects,components may be automatically replaced. FIG. 30 is a schematic viewthat illustrates a mechanism for automatically exchanging minimallyinvasive surgical instruments (e.g., those of approximately 3 mmdiameter, such as flexible laparoscopic instruments with a single gripDOF) during surgery. As shown in FIG. 30, an instrument magazine 3002has several instruments 3004 a,3004 b,3004 c stored (e.g., three, asdepicted). The instruments may be stored on a drum, linearly extended,or otherwise. In some aspects, the instruments in magazine 3002 areselected for each surgical procedure—that is, the surgeon determines theinstruments to be used for a specific procedure, and magazine 3002 isconfigured accordingly. As FIG. 30 illustrates, magazine 3002 ispositioned to allow actuator control system 3006 to advance instrument3004 a into guide tube 3008. To exchange an instrument, control system3006 withdraws instrument 3004 a from guide tube 3008 and repositionsmagazine 3002 to advance either instrument 3004 b or 3004 c into guidetube 3008. The magazine, instruments, and guide tube shown in FIG. 30are illustrative of various components described herein (e.g.,instruments, primary and secondary guide tubes, guide probes, imagingsystems (optical, infrared, ultrasound), and the like).

FIG. 30A is a schematic view that illustrates aspects of storing aninstrument or other component on a drum. Instrument 3004 is extended asdrum 3020 rotates inside magazine housing 3022. Actuator 3006 forinstrument 3004's end effector 3008 is positioned on drum 3020. Actuator3006 is illustrative of other actuator assemblies that may be used if,for example, a steerable guide tube is to be advanced instead.Instrument 3004 is coiled loosely enough so that the cable actuator forend effector 3008 does not bind within its flexible cover. FIG. 30B is aschematic view that illustrates aspects of storing automaticallyreplaceable instruments on spools 3030 mounted on individual capstans3032.

FIG. 31 is a diagrammatic perspective view that shows aspects of anillustrative minimally invasive surgical instrument assembly thatincludes a multi-jointed instrument dedicated to retraction. As shown inFIG. 31, guide tube 3102 includes a channel 3104, through which animaging system is inserted, and three channels 3106 a,3106 b,3106 c,through which surgical instruments may be inserted. Retractioninstrument 3108 is shown extending through channel 3106 c.

As depicted, retraction instrument 3108 includes a proximal instrumentbody 3110 and four serial links 3112 a-d. Four joints 3114 a-d coupleproximal instrument body 3110 and links 3112 a-d together. In oneaspect, each joint 3114 a-d is an independently controllable single DOFpitch joint. In other aspects the joints may have additional DOFs. Anactively controlled (either hand or telemanipulated) gripper 3116 ismounted at the distal end of the most distal link 3112 d via a passiveroll joint 3118. In some aspects other end effectors, or none, may besubstituted for the gripper. In one aspect the combined length of links3112 a-d and gripper 3116 is sufficient to retract tissue beyond theworking envelope of instruments that extend through channels 3106 a and3106 b. For example, the combined lengths of the links and the grippermay be approximately equal to the full insertion range (e.g.,approximately 5 inches) of the instruments. Four links and joints areshown, and other numbers of links and joints may be used. Retraction isdone using various combinations of pitching joints 3114 a-d and rollinginstrument 3108 within channel 3106 c.

For retraction, instrument 3108 is inserted so that each joint 3114 a-dis exposed one after the other. Insertion depth may be varied so thatretraction can begin at various distances from the distal end of theguide tube with various numbers of joints as the joints exit from theguide tube's distal end. That is, for example, retraction may begin assoon as joint 3114 d is inserted past the distal end of the guide tube.For retraction, gripper 3116 may grip tissue. Passive roll joint 3118prevents the gripped tissue from being torqued as instrument 3108 isrolled within channel 3106 c. In one aspect, the control system couplesthe motions of instrument 3108 and guide tube 3102. This coupled controlof motion allows tissue to be held in place by gripper 3116 as the guidetube is moved to the left or right “underneath” the retracted tissue.For example, as the distal end of guide tube 3102 is moved to the left,instrument 3108 is rolled (and joint 3114 a-d pitch may be changed) tomove gripper 3116 to the right.

FIG. 31 further illustrates an aspect of instrument position and controlwithin guide tubes. The working surgical instruments need not beinserted though guide tube channels that correspond to or are alignedwith their working position. For example, as shown in FIG. 31 the leftside working instrument does not have to be inserted through theleft-most channel 3106 c. Instead, the left side working instrument maybe inserted via the “bottom” channel 3106 b. The right side workinginstrument may then be inserted via the right-most channel 3106 a. Then,the left and right side working instruments may be controlled to work ata surgical site in alignment with the field of view of an imaging systeminserted via channel 3104 that has not been rolled or yawed. Statedanother way, the left-right axis between the working instruments'insertion channels does not have to be aligned with the left-right axisbetween the working instruments' end effectors at the surgical site orwith the left-right axis interpupillary axis of the stereoscopic imagingsystem. Further, by the control system recognizing which instrument iscoupled to each particular actuator, left-right instrument position maybe varied. For example, retraction instrument 3108 may be inserted viachannel 3106 a, the right side working instrument may be inserted viachannel 3106 b, and the left side working instrument may be inserted viachannel 3106 c. In some aspects, with appropriately shaped channelsand/or imaging systems, the imaging system may be inserted via one ofseveral channels. For example, “top” channel 3104 and “bottom” channel3106 b may be oblong shaped with a center bore that holds a cylindricalinstrument body, as shown in FIG. 20A. Consequently, an imaging systemmay be inserted via the “top” or “bottom” channel, and a workinginstrument may be inserted via the other “top” or “bottom” channel.

These descriptions of examples of various minimally invasive surgicalsystems, assemblies, and instruments, and of the associated components,are not to be taken as limiting. It should be understood that manyvariations that incorporate the aspects described herein are possible.For example, various combinations of rigid and flexible instruments andinstrument components, and of guide tubes and guide tube components,fall within the scope of this description. The claims define theinvention.

We claim:
 1. A surgical instrument assembly comprising: a guide tubecomprising a proximal end, a distal end, a first joint between theproximal and distal ends, and an intermediate position between theproximal and distal ends; an image capture component positioned at thedistal end of the guide tube, wherein the first joint of the guide tubeallows the image capture component to move while the intermediateposition remains stationary; and a surgical instrument comprising afirst body segment, a first set of cables, a parallel motion mechanism,a wrist mechanism, and a distal end component; the first body segmenthaving a proximal end, a distal end, and a longitudinal axis definedbetween the proximal end and the distal end of the first body segment;the distal end component being coupled to the wrist mechanism; the wristmechanism being configured to move the distal end component in at leastone orientation degree of freedom; the parallel motion mechanismcomprising a first joint, a second joint, a second body segment, and asecond set of cables; the first joint of the parallel motion mechanism,the second body segment, and the second joint being connected in series;the first joint of the parallel motion mechanism comprising a firsthinge having a first hinge pivot, the first hinge coupling the firstbody segment to the second body segment; the second joint comprising asecond hinge having a second hinge pivot, the second hinge beingpositioned between the second body segment and the wrist mechanism; thefirst set of cables extending through the first body segment to theparallel motion mechanism, each of the first set of cables having adistal end connected distal of the first hinge pivot; and the second setof cables each having a first end connected to the parallel motionmechanism proximal of the first hinge pivot, and each having a secondend connected to the parallel motion mechanism distal of the secondhinge pivot; wherein at least the distal end of the first body segment,the parallel motion mechanism and the distal end component of thesurgical instrument pass through the guide tube and exit the guide tubeat the intermediate position; and wherein the parallel motion mechanismheaves and sways the distal end component of the surgical instrumentwith reference to the longitudinal axis of the first body segmentwithout changing pitch and yaw of the distal end component of thesurgical instrument.
 2. The assembly of claim 1, the guide tube furthercomprising two independently controllable joints, the two independentlycontrollable joints being positioned between the distal end of the guidetube and the intermediate position to move the image capture componentwhile the intermediate position remains stationary, the first jointbeing one of the two independently controllable joints.
 3. The assemblyof claim 1: wherein a cross section of the guide tube comprises anoblong shape; and wherein the surgical instrument passes through one endof the oblong shape.
 4. The assembly of claim 1: wherein the guide tubecomprises a second parallel motion mechanism that moves the imagecapture component while the intermediate position remains stationary;wherein the first joint of the guide tube is included in the secondparallel motion mechanism; and wherein the second parallel motionmechanism heaves and sways the image capture component without changingpitch and yaw of the image capture component.
 5. The assembly of claim1, further comprising: a second surgical instrument comprising a thirdbody segment, a third set of cables, a second parallel motion mechanism,a second wrist mechanism, and a second end component; the third bodysegment having a proximal end, a distal end, and a longitudinal axisdefined between the proximal end and the distal end of the third bodysegment; the second distal end component being coupled to the secondwrist mechanism; the second parallel motion mechanism comprising a thirdjoint, a fourth joint, a fourth body segment, and a fourth set ofcables; the third joint, the fourth body segment, and the fourth jointbeing connected in series; the third joint comprising a third hingehaving a third hinge pivot, the third hinge coupling the third bodysegment to the fourth body segment; the fourth joint comprising a fourthhinge having a fourth hinge pivot, the fourth hinge being positionedbetween the fourth body segment and the wrist mechanism; the third setof cables extending through the third body segment to the secondparallel motion mechanism, each of the third set of cables having adistal end connected distal of the third hinge pivot; and the fourth setof cables each having a first end connected to the second parallelmotion mechanism proximal of the third hinge pivot, and each having asecond end connected to the second parallel motion mechanism distal ofthe fourth hinge pivot; wherein the second parallel motion mechanism ofthe second surgical instrument heaves and sways the second distal endcomponent of the second surgical instrument without changing pitch andyaw of the second distal end component of the second surgicalinstrument; and wherein at least a distal end of the second surgicalinstrument passes through the guide tube and exits the guide tube at theintermediate position.
 6. The assembly of claim 5: wherein the firstjoint of the guide tube is between the first and the second surgicalinstruments when parts of the first and the second surgical instrumentsextend from the intermediate position.
 7. The assembly of claim 5:wherein a cross section of the guide tube comprises an oblong shape;wherein the surgical instrument passes through a first end of the oblongshape; and wherein the second surgical instrument passes through asecond end of the oblong shape.
 8. A method comprising: extending aparallel motion mechanism of a surgical instrument from an intermediateposition of a guide tube, an image capture component being on the guidetube; moving the image capture component on the guide tube while theintermediate position of the guide tube remains stationary; and movingthe parallel motion mechanism of the surgical instrument to heave andsway, a distal end component of the surgical instrument without changingpitch and yaw of the distal end component of the surgical instrument;the surgical instrument comprising a first body segment, a first set ofcables, the parallel motion mechanism, a wrist mechanism, and a distalend component; the first body segment having a proximal end, a distalend, and a longitudinal axis defined between the proximal end and thedistal end of the first body segment; the distal end component beingcoupled to the wrist mechanism; the wrist mechanism being configured tomove the distal end component in at least one orientation degree offreedom; the parallel motion mechanism comprising a first joint, asecond joint, a second body segment, and a second set of cables; thefirst joint, the second body segment, and the second joint beingconnected in series; the first joint comprising a first hinge having afirst hinge pivot, the first hinge coupling the first body segment tothe second body segment; the second joint comprising a second hingehaving a second hinge pivot, the second hinge being positioned betweenthe second body segment and the wrist mechanism; the first set of cablesextending through the first body segment to the parallel motionmechanism, each of the first set of cables having a distal end connecteddistal of the first hinge pivot; and the second set of cables eachhaving a first end connected to the parallel motion mechanism proximalof the first hinge pivot, and each having a second end connected to theparallel motion mechanism distal of the second hinge pivot.
 9. Themethod of claim 8: wherein moving the image capture component comprisesmoving two independently controllable joints.
 10. The method of claim 8:wherein moving the image capture component comprises moving a secondparallel motion mechanism; and wherein the second parallel motionmechanism heaves and sways the image capture component without changingpitch and yaw of the image capture component.
 11. The method of claim 8,further comprising: extending the surgical instrument through a firstend of an oblong cross section of the guide tube.
 12. The method ofclaim 11, further comprising: extending a second surgical instrumentthrough a second end of the oblong cross section of the guide tube. 13.A surgical instrument assembly comprising: a guide tube comprising aproximal end, a distal end, and a first set of cables; a first surgicalinstrument that extends through the guide tube and exits the guide tube;a second surgical instrument that extends through the guide tube andexits the guide tube; an image capture component; a wrist mechanismcoupled to the image capture component, the wrist mechanism beingconfigured to move the image capture component in at least oneorientation degree of freedom; and a parallel motion mechanismcomprising a first joint, a second joint, a body segment, and a secondset of cables, the parallel motion mechanism being coupled between theguide tube and the image capture component, the parallel motionmechanism being configured to heave and sway the image capture componentwithout changing pitch and yaw of the image capture component; the firstjoint, the body segment, and the second joint being connected in series;the first joint comprising a first hinge having a first hinge pivot, thefirst hinge coupling the distal end of the guide tube to the bodysegment; the second joint comprising a second hinge having a secondhinge pivot, the second hinge being positioned between the body segmentand the wrist mechanism; the first set of cables extending through theguide tube to the parallel motion mechanism, each of the first set ofcables having a distal end connected distal of the first hinge pivot;and the second set of cables each having a first end connected to theparallel motion mechanism proximal of the first hinge pivot, and eachhaving a second end connected to the parallel motion mechanism distal ofthe second hinge pivot.
 14. The surgical instrument assembly of claim13: wherein a longitudinal axis is defined between the proximal anddistal ends of the guide tube, and wherein the wrist mechanism allowsthe image capture component to move in yaw with reference to thelongitudinal axis.
 15. The surgical instrument assembly of claim 13:wherein a longitudinal axis is defined between the proximal and distalends of the guide tube, and wherein the wrist mechanism allows the imagecapture component to move in pitch with reference to the longitudinalaxis.
 16. The surgical instrument assembly of claim 13: wherein thefirst surgical instrument comprises a second body segment, a third setof cables, a second parallel motion mechanism, a second wrist mechanism,and a distal end component; and wherein the second parallel motionmechanism of the first surgical instrument heaves and sways the distalend component of the first surgical instrument without changing pitchand yaw of the distal end component of the first surgical instrument;the second body segment having a proximal end, a distal end, and alongitudinal axis, defined between the proximal end and the distal endof the second body segment; the distal end component being coupled tothe second wrist mechanism; the second parallel motion mechanismcomprising a third joint, a fourth joint, a third body segment, and afourth set of cables; the third joint, the third body segment, and thefourth joint being connected in series; the third joint comprising athird hinge having a third hinge pivot, the third hinge coupling thesecond body segment to the third body segment; the fourth jointcomprising a fourth hinge having a fourth hinge pivot, the fourth hingebeing positioned between the third body segment and the wrist mechanism;the third set of cables extending through the second body segment to thesecond parallel motion mechanism, each of the third set of cables havinga distal end connected distal of the third hinge pivot; and the fourthset of cables each having a first end connected to the second parallelmotion mechanism proximal of the third hinge pivot, and each having asecond end connected to the second parallel motion mechanism distal ofthe fourth hinge pivot.
 17. The surgical instrument assembly of claim13: wherein the first surgical instrument comprises a flexible portionbetween a position at which the first surgical instrument exits theguide tube and a distal end of the first surgical instrument.
 18. Thesurgical instrument assembly of claim 13, further comprising: atransmission mechanism coupled to each of the first set of cables, thetransmission mechanism being positioned proximal of the guide tube, andthe transmission mechanism being configured to apply a tensile force onone or more of the cables in the first set of cables to change the heaveor sway of the image capture component.
 19. The surgical instrumentassembly of claim 1, further comprising: a transmission mechanismcoupled to each of the first set of cables, the transmission mechanismbeing positioned proximal of the guide tube, and the transmissionmechanism being configured to apply a tensile force on one or more ofthe cables in the first set of cables to change the heave or sway of thedistal end component.